Medical Progress

Disorders of Metabolism 1971

JOHN H. MENKES, M.D., Los Angeles

OVER THE PAST TWENTY YEARS the number of dis- The metabolic defect in PKU is a failure in the orders to which we are able to assign a known hydroxylation of to . Phen- enzymatic defect in amino acid metabolism has ylketonuric children are born with only slightly increased strikingly. Even so, they are relatively elevated phenylalanine levels, but due to uncommon, and their importance lies, in part, in inactivity or absence of phenylalanine hydroxyl- the insight they offer into the normal develop- ase, the amino acid derived from food proteins ment and function of the human . accumulates in serum and cerebrospinal fluid In some of the disorders, such as , and is excreted in large quantities. In lieu of the and hydroxyprolinemia, the as- normal degradative pathway phenylalanine is sociation of a neurologic disturbance may be converted to phenylpyruvic acid, phenyllactic fortuitous and merely the result of subjecting acid and phenylacetylglutamine. The transam- retarded children, a highly selected group, to ination of phenylalanine to phenylpyruvic acid is biochemical examination. A survey of the normal sometimes deficient for the first few days of life, adult population for the incidence of inborn er- and the age when phenylpyruvic acid may be rors of amino acid metabolism is needed to deter- first detected varies from 2 to 34 days. From the mine which of the conditions mentioned in this first week of life on, o-hydroxyphenylacetic acid review represent harmless metabolic variants. is also excreted in large amounts. Alterations within the brain are non-specific, usually confined to white matter, and probably Phenylketonuria (PKU) is an inborn error of progress in severity with increasing age. They metabolism due to the inability to convert phen- include an interference with the normal matura- ylalanine to tyrosine; it produces mental retarda- tion of the central nervous system, defective tion, , and imperfect hair pigmentation. myelination, and a cystic degeneration of white Folling in 1934 first called attention to the con- matter.2 dition.' Since then the disease has been found in Phenylketonuric infants appear normal at birth. all parts of the world, although it is rare in Ne- During the first two months of life, , of- groes or in Jews of European descent. Its fre- ten projectile, and irritability are frequent. By quency in the United States, as determined by four to nine months delayed intellectual develop- screening programs, is approximately 1 in 14,000. ment becomes apparent.3 In the classic case, It is transmitted as an autosomal recessive dis- mental retardation may be severe, precluding order. speech and toilet training, and the Intelligence Quotient is under 50. Seizures are common in From the Division of Pediatric Neurology, University of California, Los Angeles, Center for the Health Sciences, and the Veterans Admin- the more severely retarded. These usually start istration Hospital, Brentwood. Original research reported in this review is supported by Research before 18 months of age and may cease spon- Grants NB 06938 from the National Institutes of Health, and by grants from the National Genetic Foundation, and Childrens' Brain Diseases. taneously. During infancy they may take the Reprint requests to: Division of Pediatric Neurology, University of form of infantile spasms, and later grand mal at- California, Los Angeles, Center for the Health Sciences, Los Angeles, Ca. 90024 (Dr. J. H. Menkes). tacks.

14 OCTOBER 1971 * 115 * 4 TABLE 1.-Screening Tests for Metabolic Defects addition of a dilute solution of 2,4-dinitrophenyl- Ferric Nitro- hydrazine produces a copious yellow precipitate Condition Chloride DNPH prusside in both fresh and old specimens (Table 1). For Phenylketonuria Green + routine screening on infants a simple stick test Maple Syrup Disease Navy Blue + Tyrosinosis Pale Green + (Phenistix®) is available for use on wet diapers. (transient) Confirmatory evidence can be obtained by find- Green Brown + ing an elevation of plasma phenylalanine. These Hyperglycinemia Purple + Methylmalonic Aciduria Purple + may already be abnormal in the cord blood of - + PKU infants, and rise rapidly within a few hours - + of birth. Inasmuch as there may be a delay in Glutathioninuria - + the appearance of phenylpyruvic acid, both the ferric chloride and the dinitrophenylhydrazine tests are inadequate for the diagnosis of PKU dur- The typical patient is blond and blue eyed, ing the neonatal period. A program for routine with normal, and often pleasant features. The screening involving the microbiological or spec- skin is rough and dry, and there may be eczema. trofluorometric estimation of blood phenylalanine A peculiar musty odor, attributable to phenyl- levels has been instituted in California.6 acetic acid, may suggest the diagnosis. Signifi- cant neurological abnormalities are rare, although The widespread use of screening programs to microcephaly, and a mild increase in muscle tone, detect the newborn infant whose blood phenyl- particularly in the lower extremities, may be pres- alanine concentration is higher than normal has ent. Older children are restless and hyperactive; uncovered several other conditions that are as- and are inclined to self-stimulative movements sociated with elevated blood phenylalanine levels of the body and hands.. In institutionalized pa- during the neonatal period.7 tients there may be intellectual deterioration, Aside from phenylketonuria a variant, previ- owing perhaps to environment, perhaps to the ously termed "atypical phenylketonuria," is the natural history of the disease. most common. On a normal protein intake pa- A variety of electroencephalographic abnor- tients with this condition have blood phenylala- malities has been found, but hypsarrhythmic pat- nine between 7 mg and 20 mg per 100 ml. This terns, recorded even in the absence of seizures, contrasts with the classic PKU patient whose phen- and single and multiple foci of spike and poly- ylalanine levels are 20 mg per 100 ml or higher. spike discharges are the most common.4 The distribution of this entity differs from Untreated PKU is not invariably accompanied that of phenylketonuria, with a relatively high by intellectual deficit. There are a number of prevalence amongst Jews of European descent. phenylketonuric persons with intelligence quo- Less commonly, a defect in phenylalanine hy- tients above 90, athough having classic biochem- droxylation is coupled with a temporary or per- ical features of the condition. Although the manent abnormality of phenylalanine trans- incidence of spontaneous abortions is high, a amination. In these patients the excretion of number of PKu women have had children; most phenylpyruvic and o-hydroxyphenylacetic acids of the offspring, although heterozygous for PKU, is inappropriately low for the serum phenylalanine showed prenatal and postnatal growth retarda- concentrations, and the ferric chloride test is neg- tion, microcephaly, severe intellectual delay, and ative on a normal diet and may become only in a few instances major congenital malforma- slightly positive during a phenylalanine load. In tions. It seems likely that the high amino acid yet another variant the phenylalanine tolerance level in the pregnant PKU mother may damage the improves gradually over the first few months of fetus.5 life, but while the ability to metabolize phenylal- in it is The diagnosis of PKU can be suspected from anine is greater than PKU, never normal. the clinical features of the disease and from the In addition, elevated blood phenylalanine lev- examination of the patient's urine by the addition els are observed in a large proportion of prema- of ferric chloride. In inadequately preserved ture infants, particularly those receiving a high specimens, phenylpyruvic acid decomposes and protein formula. In all these patients tyrosine the ferric chloride test becomes negative. The levels are decidedly increased as well.

CALIFORNIA MEDICINE 15 The Western Journol of Medicine In view of the existence of these variants of pear and the electroencephalogram often reverts PKU, the diagnosis of PKU can only be made if the to normal. Abnormally blond hair regains its nat- following criteria are satisfied: ural color. The effects on mental ability are less * Blood phenylalanine 20 mg per 100 ml or clear-cut. In the experience of Fuller and Shu- greater, with normal blood tyrosine levels. man"1",2 treated PKU children fell into a tri-modal * In untreated infants a positive ferric chloride distribution with respect to their I.Q. The age test by 2 to 36 days of age. at which therapy was initiated did not determine * When the infant is temporarily returned to a into which of the three groups a given child fell. normal diet between four and nine months of age, However, infants under 18 months of age whose the blood phenylalanine concentration rises to 20 blood phenylalanine levels were maintained un- mg per 100 ml or higher, and he begins to excrete der 5 mg per 100 ml had a decrease in intel- phenylpyruvic acid. lectual performance. Patients who were started * After an acute phenylalanine load, the blood on treatment before six months of age, some of tyrosine concentration does not rise. whom may have had phenylalaninemia, were The distinction between PKU and phenylala- represented only in the two higher performance ninemia is more than academic. Children with modes. Even when the measured I.Q. is normal, phenylalaninemia do not fare well on dietary ther- neuropsychological handicaps, which result in apy. Their phenylalanine levels tend to fall pre- poorer school progress than would be predicted cipitously, and they are likely to have side reac- from the I.Q. alone are common.'3 Minor struc- tions such as hypoglycemia and symptoms of tural malformations of the central nervous sys- protein deficiency. These have been known to tem may well be responsible for this difference.2 induce intellectual retardation and othei neuro- In other instances nornal intellectual develop- logical symptoms.8 ment may be possible in the absence of any The generally accepted therapy for PKU re- dietary management. Finally, in a third group stricts the dietary intake of phenylalanine, using dietary treatment may be beneficial when a commercially available casein hydrolysate from phenylalanine concentrations are maintained suf- which the amino acid has been removed. Gen- ficiently high to allow normal protein synthesis. erally, patients tolerate this diet well, and within The duration of treatment is also controver- one to two weeks the serum phenylalanine con- sial, and various centers have advocated termi- centration becomes normal. Various complica- nating dietary restriction between 4 and 15 years tions of dietary treatment, all due to insufficient of age.14 In a more recent study the age at which intake of phenylalanine, include osteoporosis, the diet was discontinued was not a factor in poor weight gain, and cutaneous lesions. There is the child's ultimate performance. Rather, dis- also some evidence that prolonged nutritional continuation of the diet was followed by a decre- deprivation during infancy interferes with intel- ment in I.Q. of those children who had been lectual development.9 under strict dietary control (blood phenylalanine Sample menus low in phenylalanine have less than 9 mg per 100 ml) but not of those been given in the literature.10 Frequent serum whose blood phenylalanine had been maintained phenylalanine determinations are essential to en- at higher levels.12 sure adequate regulation of the diet. As restric- tion of phenylalanine intake has definite inherent Maple Syrup Disease risks, the criteria for initiating treatment of in- Maple syrup disease is a familial cerebral de- fants needs re-evaluation. Infants whose phenyl- generative disease due to a defect in branched- alanine levels remain below 20 mg per 100 ml chain amino acid metabolism, and is character- do not appear to become retarded, and there is ized by a sweet, maple syrup-like odor in the no justification for treating them. At present we urine. It was first described in 1954 by Menkes have insufficient evidence for or against the need et al.'4 The condition occurs in all races, with of treating children whose blood phenylalanine an autosomal recessive inheritance. level is higher than 20 mg per 100 ml but who The disease is characterized by the accumula- do not excrete phenylpyruvic acid. Restriction of tion of three branched-chain keto acids: alpha- the diet is therefore indicated. ketoisocaproic acid (KIcA), alpha-ketoisovaleric On a low phenylalanine diet seizures disap- acid (KivA), and alpha-keto-beta-methylvaleric

16 OCTOBER 1971 * 115 * 4 TABLE 2.-Detects in Metabolism Clinical Featu'res Enzymatic Biochemical Disease Defect MentalAccompanyingRetaidaAt7on Findings Argininosuccinic Argininosuccinase Seizures, white brittle Elevated urine, spinal aciduria" hair (trichorrhexis fluid argininosuccinic nodosa') acid. Citrullinuriatm Argininosuccinic None Elevated blood, urine acid synthetase citrulline. Elevated blood ammonia after high protein meal. ' Ornithine trans- Intermittent coma, Elevated blood ammonia. carbamylase attacks of vomiting Carbamylphosphate Intermittent coma, Elevated blood ammonia. synthetase2' cyclic neutropenia intolerance2" Unknown; defect Intermittent coma, Increased plasma lysine in arginase spasticity and , increased blood ammonia. acid (KmA ). These are the derivatives of , As in PKU a diet containing restricted amounts and , respectively. In maple of the inadequately handled amino acids-in this syrup disease a single gene defect involves more instance leucine, isoleucine and valine-has been than one . It is likely that the af- used in treatment. For optimal results the diet fected in maple syrup disease have a common should be initiated during the first few days of polypeptide chain which is under the control life, and frequent quantitation of the serum amino of a single gene. As a consequence of the defect, acids is necessary. A sample synthetic diet has the three previously mentioned keto acids ac- been described.16 cumulate in serum and cerebrospinal fluid, and A few children maintained on such a regimen are excreted in large amounts.15 Plasma levels of have been known to achieve a fairly adequate the respective amino acids are elevated second- intellectual development. arily. The structural alterations in the nervous sys- tem are similar to those seen in PKU, but more Defects in Urea Cycle Metabolism severe. Five inborn errors in the urea cycle have been In most patients opisthotonos, intermnittent in- described, with one defect at each of the five crease in muscle tone and respiratory irregulari- steps in the conversion of ammonia to urea. They ties appear within the first week of life, with include argininosuccinic aciduria, citrullinuria, subsequent rapid cerebral deterioration. Severe and two conditions termed hyperammonemia, the hypoglycemia develops in about half of them. more common being due to a defect in the con- As with PKU, a number of variants have been version of ornithine to citrulline. Congenital ly- reported. In one type patients have intermittent sine intolerance is also associated with periodic ataxia, drowsiness and behavior disturbances. ammonia intoxication, most likely due to inter- Another variant has been observed in a retarded ference by lysine with the enzyme arginase. child, while in the most recent described entity, These diseases have in common an autosomal re- the condition responded to thiamine. cessive transmission, and a clinical picture high- Maple syrup disease is diagnosed by the char- lighted by moderate to severe mental retardation, acteristic odor of the patient and a positive 2,4- seizures, vomiting, and intermittent episodes of dinitrophenylhydrazine test on the urine. The stupor or coma. In all of them the enzyme defect ferric chloride test sometimes produces a navy is partial, for complete failure of ureogenesis blue color. Chromatography of the urine for keto would be incompatible with life. Neurological acids, or of the serum for amino acids confirms symptoms are believed to result from chronic the diagnosis. hyperammonemia, and restriction of protein in-

CALIFORNIA MEDICINE 17 The Western Journal of Medicine take to 1 to 2 grams per kg of body weight per In most there is intimal thickening and fibrosis, day will often free the patient of symptoms. The and both arterial and venous thrombosis is com- conditions are outlined in Table 2. mon in brain and various other organs. The rela- Aside from the above diseases, hyperammone- tionship between the metabolic defect and the mia is also seen in chronic liver disease and in vascular changes is unclear. other genetic disorders whose biochemical basis The condition is transmitted in an autosomal is still unclear. These include a syndrome of fa- recessive mode, Homocystinuric infants appear milial protein intolerance, and inter'mittent hy- normal at birth and their early development is perammonemia with abnormally high levels of unremarkable until seizures, developmental slow- ornithine in- the blood anid homocitrullinie in the ing or cerebrovascular accidents occur between urine.2 5 and 9 months of age. has been recognized by 18 months, and is invariable in Histidinemia older children. Secondary glaucoma and cata- Histidinemia, which may be a harmless meta- racts are common. In the typical older child the bolic variant, has been described in several chil- hair is sparse and brittle, and there are multiple dren who presented with a variety of minor erythematous blotches. The extremities and dig- neurologic disturbances, such as delayed speech its are long, giving the pseudo Marfan's appear- secondary to impaired auditory memory.23 The ance. About half of the patients experience major condition is due to an interruption in the first thrombo-embolic episodes. step of the catabolic pathway, the con- The diagnosis of homocystinuria is suggested version of histidine to urocanic acid. by the appearance of the patient, and may be The diagnosis is made by the addition of ferric confirmed by a positive urinary cyanidenitro- chloride to the urine, which results in the ap- prusside reaction (Table 1). The test is also posi- pearance of a permanent olive green color (Table tive in the presence of large amounts of cystine 1). The diagnosis is confirmed by the elevation and acetone. of histidine in blood, and by enzymatic assays. Restriction of intake lowers the Treatment of histidinemia with a low histidine plasma methionine of homocystinuric children, diet has been proposed, but in view of the un- and eliminates thie abnormally high excretion of certainty of the natural course of the disease, we homocystine.27 Although the biochemical picture have no way of judging its effectiveness. can be improved by these means, there is no evidence for clinical benefit. Homiocystinuria Hoinocystinuria, which was discovered by Other Rare Metabolic Defects Field24 in 1962, is an inbom error of methionine Various studies have appeared in the literature metabolism manifesting itself by multiple throm- describing a single family or a few patients with boembolic episodes, ectopia lentis, and mental neurological disturbances associated with an ab- retardation. The incidence is second to that of normality in the amino acid pattern of serum or PKu amongst the inbom errors of amino acid me- urine. Sonme of these conditions are listed in tabolism. Table 3. The metabolic defect is one of cystathionine Several other disorders, often discussed together synthetase, the enzyme catalyzing the formation with the aminoacidurias, are manifestated by in- of cystathionine from homocysteine and serine. termittent episodes of vomiting, lethargy, acidosis As a result of the block, increased amounts of and the excretion of ketone bodies. Many of homocystinie, and its precursor methionine, are these are detected by the purple color given to found in urine and plasma. Two variants of the the ferric chloride reagent by large quantities of disease are now distinguished: in one administra- urinary acetone (Table 1). They are also in- tion of oral pyridoxine does not alter homocys- cluded in Table 3. tine excretion, while in the other large doses of This brief review has attempted to summarize the vitamin (500 mg a day or higher) eliminate our current knowledge with respect to the vari- homocystine from plasma and urine. ous disorders of amino acid metabolism. Al- The primary structural alterations in the dis- though a number of other disorders still remain ease are noted in blood vessels of all calibers.25 to be discovered, one suspects that the vast ma-

18 OCTOBER 1971 * 15 * 4 TABLE 3.-Some Rare Defects in Amino Acid Metabolism Associated with Neurologic Symptoms'm Clinical Features Accompanying Disease Enzymatic Delect Mental Retardation Biochemical Findings Cystathioninuria Cystathioninase Retardation in some, but others Urine, brain cystathionine normal. elevated

Hyperglycinemia PropionylCoA Early ketosis, precipitated Elevated blood . (Ketotic) Carboxylase by protein intake, progressive Severe ketosis after leucine extrapyramidal signs. load. Unusual ketone bodies. Methyl Malonic Methylmalonyl Metabolic Acidosis, intermittent Ketoacidosis, increased Acidemia CoA Carbonylase cdma. excretion of methylmalonic Mutase acid, elevated glycine, ammonia. "Sweaty Feet" Fatty acid Lethargy, acidosis, striking Excretion of butyric and Syndrome Dehydrogenase urinary odor. hexanoic acids.

Isovaleric Isovaleryl CoA Recurrent acidosis, comna, Isovaleric acid in urine, Acidemia Dehydrogenase unusual body, urine odor. serum.

Lactic Acidemia Unknown Recurrent acidosis, coma. Accumulation of lactic and pyruvic acids. Hyperprolinemia A. Renal hypoplasia, deafness, Elevated plasma, urine oxidase seizures. (Some patients proline. B. Pyrroline-5- are normal) carboxylate dehydrogenase

Hyperlysinemia Unknown and seizures, but Increased plasma and also in normal child. urinary lysine. Hartnup's disease Transport of neutral Intermittent ataxia, rash, Increased output of amino acids photophobia, intellectual dis- amino acids, indolic turbances, no mental retardation. compounds. Intestinal Very rare in U.S.A. transport of impaired. Valine transaminase Vomiting, failure to thrive, Increased blood and nystagmus, mental retardation. urine valine. No in- crease in keto acid excretion.

Sarcosinemia ? Mental retardation. Increased blood and oxidase urine sarcosine, ethanolamine. Hyperbeta- g3eta-alanine- Seizures commencing at birth, Plasma urine beta- alaninemia alpha-Ketoglutarate Somnolence alanine and beta- transaminase aminoisobutyric acid elevated. Urinary gamma-aminobutyric acid elevated. Hyperalaninemia Pyruvate decarboxylase Intermittent cerebellar ataxia Increased serum alanine, and choreoathetosis lactate, and pyruvate.

Carnosinemia ?Camosinase Grand mal and myoclonic seizures. Increased serum, urine Mental retardation. camosine, increased CSF homocamosine. Beta-Hydroxy- ?Methylerotonyl- Similar to infantile spinal Increased urine isovaleric CoA carboxylase muscular atrophy, urine smells beta-hydroxyisovaleric Aciduria and like that of a cat. acid, beta-methylcroto- Beta-Methyl nylglycine. Crotonylglycinuria

CALIFORNIA MEDICINE 19 The Western Journal of Medicine Figure 1.-Normal urinary amino acid chromatogram. An equivalent of 60 jug creatinine was applied. Chromatography on Whatman No. 40 paper, developing solvents: butanol-glacial acetic acid-water (120: 30:50) (BU-AC), and phenol-ammonium hydroxide (200:1) (Ph-Am). Amino acids visualized by ninhydrin spray. (Cly - glycine; ser = serine; Glut A = ; Threo = threonine; Hist = histidine; GIUNH2 = ; BAIB = .8-aminoisobutyric acid; 3-Me Hist = 3-methylhistidine; val = valine.) The subject excretes a large amount of BAIB, an asymptomatic metabolic variant. jority of patients having a biochemical defect in Ferric Chloride test: 3 to 5 drops of a 10 per- this area of intermediary metabolism can now be cent ferric chloride solution in 2 N hydrochloric diagnosed and classified, and possibly improved acid are added to 1 ml of urine without previous with the therapeutic armamentarium which we acidification. The color change occurring imme- have currently on hand. diately and over the subsequent 3 to 4 minutes is noted. The green color produced by urine con- Diagnosis of Amino Acid Disorders taining phenylpyruvic acid fades within 30 min- utes, while that produced by the tyrosine deriva- When a patient's neurological disease cannot tive, p-hydroxyphenylpyruvic acid, is even more be explained on the basis of a congenital or transient. By contrast the olive-green color seen acquired defect of the nervous system, and es- in urine from patients with histidinemia is per- pecially when a like condition exists in the im- manent. The urine in maple syrup disease some- mediate family, the physician must consider the times yields a navy blue color with this reagent. diagnosis of an inborn metabolic error. In many When ketones or salicylates are excreted, the of these conditions the clinical picture is either urine gives a purple color after addition of ferric nonspecific or has not yet been completely de- chloride. Phenothiazines and isoniazid produce fined. The diagnosis is therefore made by dem- a green color. onstrating an abnormality of the chemical constit- DNPH Test: To 1.0 ml of urine, 0.2 ml of a 0.5 uents in body fluids or tissues. percent solution of 2,4-dinitrophenylhydrazine in 2 N hydrochloric acid is added drop by drop. A Urinary Screening Tests definite yellow precipitate, forming within 1 min- For the routine clinical screening of aminoaci- ute, represents a positive reaction. This reac- duria we advocate the use of three procedures tion is given by carbonyl compounds including (Table 1). acetone, and keto acids such as phenylpyruvic

20 OCTOBER 1971 * 115 * 4 Figure 2.-Upper frame shows urinary amino-acid chromatogram in phenylketonuria. The conditions are the same as those employed for Figure 1. The spot representing phenylalanine is prominent in the upper left-hand corner of the chromatogram. Lower frame is urinary amino-acid chromatogram in maple syrup disease; The three branched-chain amino acids are prominent in the upper left-hand corner.

CALIFORNIA MEDICINE 21 The Western Journal of Medicine acid, and the branched-chain keto acids excreted in maple syrup disease. Although a precipitate may form, the reagent is stable at room temper- ature for several months. Nitroprusside-Cyanide Test: To 5 ml of urine, several drops of concentrated ammonium hydrox- ide and 2 ml of a 5 percent solution of sodium cyanide are added. After 5 to 10 minutes, a few drops of a 5 percent solution of sodium nitro- prusside are added. A burgundy color represents a positive reaction. It is obtained in the presence of homocystine, cystine, and laige amounts of acetone. The reagents are stable in plastic bot- tles for several months at ice box temperature. In our experience more than 90 percent of pa- tients with disorders of amino acid metabolism are detected by these relatively simple tests and by a reliable blood ammonia determination.t In the presence of a positive reaction further confir- mation of the nature of the inborn metabolic error requires qualitative and quantitative chromatog- raphy and enzyme assays. Qualitative amino acid chromatography is done by a number of hospitals and university centers, and in most instances is sufficient for diagnostic purposes. A commonly used procedure employs previously desalted urine, which is subjected to two-dimensional chromatography. A variety of acidic and alkaline developing solvents can be Figure 3.-Urinary keto-acid chromatogram in maple syrup disease. The two major spots represent used to develop the chromatogram. Amino acids the keto acid analogues of the three branched-chain are visualized by spraying with ninhydrin. When amino acids. (KICA: alpha-keto-isocaproic acid; KIVA: alpha-keto-isovaleric acid). Developing solvent: buta- normal urine tontaining 30 to 60 jug of creatinine nol-ethanol-0.5 M ammonium hydroxide (130.20:50). is chromatographed, the principal amino acids Spots visualized by their natural color. visualized are glycine, serine, alanine, histidine, glutamine, and lysine (Figure 1). Taurine and sional thin-layer chromatography. In maple syrup cystine are often lost when the urine is desalted, disease the two major spots represent the keto while glutamic acid indicates bacterial decompo- acid analogues of the three branched-chain amino sition of glutamine. While traces of phenylalanine acids (Figure 3). This procedure is available in are detected in the urine of nornal persons, a a number of California institutions. Quantitative child with phenylketonuria excretes large amounts amino acid chromatography, which is performed of this amino acid (Figure 2). In maple syrup by a California commercial laboratory, is less disease the excretion of branched-chain amino helpful as an initial screening device, and cer- acids is strikingly increased (Figure 2). tainly more expensive and laborious. It can be A method of urinary keto-acid chromatography done* on selected patients whose initial studies employed by us28 can be used to detect a num- suggest a defect in amino acid metabolism. In ber of metabolic disorders characterized by most instances children should be put into hos- abnormalities in ketone excretion, notably phen- pital and their protein intake strictly monitored ylketonuria, maple syrup disease, and the before this procedure. hyperglycinemias. The ketone bodies are precip- Enzymatic assays are performed on liver and itated in the form of their 2,4-dinitrophenylhy- kidney biopsy material, and on fibroblast cultures drazone derivatives and subjected to uni-dimen- derived from skin biopsy specimens. For this tDr. Samuel Bessman, Department of Pharmacology, University of *In a few California institutions; in Los Angeles by Dr. K. N. F. Southern California. Shaw of Children's Hospital.

22 OCTOBER 1971 * 1 15 * 4 14. Menkes JH, Hurst PL. Craig JM: A new syndrome: Progressive purpose the enzyme assays have to be well stand- familial infantile cerebral dysfunction associated with unusual urinary ardized, and referral to a center interested in a substance. Pediatrics 14:462, 1954 15. Menkes JH: Maple syrup disease-Isolation and identification of given disorder is necessary. organic acids in the urine. Pediatrics 23:348-353, 1959 16. Snyderman SE: The therapy of maple syrup urine disease. Am J Dis Child 113:68-73, 1967 17. Allan JD, Cusworth DC, Dent CE, et al: A disease, probably REFERENCES hereditary, characterized by severe mental deficiency and a constant gross abnormality of amino acid metabolism. Lancet 1:182, 1958 1. Folling A: Uber Ausscheidung von Phenylbrenztraubensaure in den Harn als Stoffwechselanomalie in Verbindung mit Imbezillitat. 18. McMurray WC, Rathbun JC, Mohyuddin F, et al: Citrullinuria. Ztschr physiol. Chem 227:169-176, 1934 Pediatrics 32:347-357, Sep 1963 2. Malamud N: Neuropathology of phenylketonuria. J Neuropathol 19. Russell A, Levin B, Oberholzer VC, et al: Hyperammonaemia- Exp Neurol 25:254, 1966 A new instance of an inborn enzymatic defect of the biosynthesis of 3. Partington MW: The early symptoms of phenylketonuria. Pedi- urea. Lancet 2:699-700, 1962 atrics 27:465, 1961 20. Hommes FA, de Groot CJ, Wilmink CW, et al: Carbamylphos- 4. Watson CW, Nigam MP, Paine RS: Electroencephalographic ab- phate synthetase deficiency in an infant with severe cerebral damage. normalities in phenylpyruvic oligophrenia. Neurology 18:203-207, 1968 Arch Dis Child 44:688-693, 1969 5. Mabry CC, Denniston JC, Coldwell JG: Mental retardation in 21. Colombo JP, Burgi W, Richterich R, et al: Congenital lysine in- children of phenylketonuric mothers. N Engl J Med 275:1331, 1966 tolerance with periodic ammonia intoxication: A defect in L-lysine 6. Cunningham GC: Two years of PKU testing in California. Calif degradation. Metabolism 16:910-925, 1967 Med 110:11-16, 1969 22. Shih VE, Efron ML, Moser HW: Hyperornithemia. hyperam- 7. Menkes JH, Holtzman NA: Neonatal hyperphenylalaninemia: A monemia and homocitrullinuria. Am J Dis Child 117:83, 1969 differential diagnosis Neuropaediatrie 1:434-446, 1970 23. Ghadimi H, Partington MW, Hunter A: A familial disturbance 8. Rouse BM: Phenylalanine deficiency syndrome. J Pediatr 69:246, of histidine metabolism. N Engl J Med 165:221, 1961 1966 24. Carson NAJ, Cusworth DC, Dent CE, et al: Homocystinuria- 9. Hanley WB, Linsao L, Davidson W, et al: Malnutrition with A new inborn error of metabolism associated with mental deficiency. early treatment of phenylketonuria. Pediatr Res 4:318-327, 1970 Arch Dis Child 38:425-436, Oct 1963 10. Kennedy JL: Phenylketonuria, In Gellis S, Kagan B (Eds): Cur- rent Pediatric Therapy-Vol 4. Philadelphia, W.B. Saunders Co, 1970, 25. Gibson JB, Carson NA, Neill DW: Pathological findings in pp 511-515 homocystinuria. J Clin Pathol 17:427-437, 1964 26. Menkes JH: Metabolic diseases of the nervous system, In Brenne- 11. Fuller RN, Shuman JB: Phenylketonuria and intelligence: Tri- mann-Kelley (Eds): Practice of Pediatrics-Vol. 4. New York, Harpers modal response to dietary treatment. Nature 221:639-642, 1969 & Row Inc., 1971 12. Fuller R, Shuman J: Treated phenylketonuria: Intelligence and Publishers, blood phenylalanine levels. Am J Ment Defic 75:539-545, 1971 27. Carson NAJ, Carre IJ: Treatment of homocystinuria with pyri- 13. Hackney IM, Hanley WB, Davidson W, et al: Phenylketonuria: doxine-A preliminary study. Arch Dis Child 44:387-392, 1969 Mental development, behavior and termination of low phenylalanine 28. Menkes JH: The pattern of urinary alpha keto acids in various diet. J Pediatr 72:646-55, 1968 neurological diseases. AMA J Dis Child 99:500, 1960

ANTIBIOTICS IN PANCREATITIS "I use antibiotics routinely in all patients in whom I make the diagnosis of pancreatitis. The infections I have seen associated with the pancreas are most commonly Gram-negative, and therefore I use a broad-spectrum antibiotic. Since the patient needs intravenous fluids anyway, I pick out one that can be given intravenously. Then the patient doesn't have to be stuck and have this bother during the rest of his illness. I commonly use tetracycline or Keflin® as the drug of choice. I do not use some of the antibiotics which in themselves may be associated with complications. Therefore I don't use Kantrex,® for example, as my initial antibiotic. Nor do I use chloramphenicol, which may be associated with other complications. I pick out a safe broad-spectrum antibiotic which can be administered intravenously."1 -GEORGE L. JORDAN, JR., M.D.. Houston Extracted from Audio-Digest Surgery, Vol. 16, No. 21, in the Au- dio-Digest Foundation's subscription series of tape recorded pro- grams. For subscription information: 619 S. Westlake Ave., Los ngmeles, Ca. 90057

CALIFORNIA MEDICINE 23 The Western Journal of Medicine