Clinical and Genetic Profile of Avellino Corneal Dystrophy in 2 Families from North India

OPHTHALMIC MOLECULAR GENETICS Clinical and Genetic Profile of Avellino Corneal Dystrophy in 2 Families From North India

Preeti Paliwal, MSc; Jaya Gupta, DNB, FICO; Radhika Tandon, MD, DNB, FRCS(Edin), FRCOpth; Arundhati Sharma, PhD; Rasik B. Vajpayee, MS, FRCS(Edin), FRANZCO

Objective: To report Avellino corneal dystrophy and un- cal examination was not done because no surgical inter- derlying R124H mutation in 2 families of Indian origin. vention was undertaken.

Methods: Peripheral blood was collected in EDTA for Conclusions: To our knowledge, this is the first report genomic DNA isolation from leukocytes of all affected of Avellino corneal dystrophy from India clinically di- and unaffected individuals. Amplification of transform- agnosed as granular corneal dystrophy, emphasizing that ing growth factor ␤-induced gene (TGFBI) using poly- TGFBI screening is essential for the accurate diagnosis merase chain reaction followed by direct sequencing was and classification of corneal dystrophies. carried out to determine the mutations underlying the disorder. A detailed clinical evaluation was undertaken Clinical Relevance: Molecular genetics is a useful to establish a genotype-phenotype correlation. tool for accurate diagnosis and classification of corneal dystrophies. All autosomal dominant stromal dystro- Results: R124H mutation resulting from a missense het- phies should be screened for underlying mutations in erozygous substitution of G to A at nucleotide 418 of TGFBI because the clinical and phenotypic appearance TGFBI was detected in all affected members of the 2 fami- is variable. lies. The affected individuals were clinically diagnosed as having granular corneal dystrophy. Histopathologi- Arch Ophthalmol. 2009;127(10):1373-1376

VELLINO CORNEAL DYSTRO- families originating from the Italian prov- phy is characterized by the ince near Naples.8 Subsequently, with presence of gray-white dis- widespread availability of molecular di- crete granular deposits in agnostic techniques, it has also been re- the subepithelial and an- ported from Germany,3 Ireland,9 Eu- terior stromal corneal layers with or with- rope,7 Japan,10-12 France,13 South Korea,14,15 A 1,2 16 17 out discernible lattice lines in the stroma. the United Kingdom, and Iran. These lattice lines develop in the second Despite specific TGFBI mutations being and third decade or even later and differ associated with each of these corneal dys- from the ones present in typical lattice cor- trophies, atypical and variable pheno- neal dystrophy in being larger, denser, types18-21 along with extensive intrafamil- whiter, and more spiculated.3 In the most ial and interfamilial variations22 are seen advanced form of the disorder, stromal and genotype-phenotype correlation is not haze emerges.1 Histologically, these de- always possible. Author Affiliations: Laboratory posits stain with Masson trichrome and We studied 5 affected individuals from of Cyto-Molecular Genetics, Congo red and are seen as discrete hya- 2 unrelated, nonconsanguineous Indian Department of Anatomy line and fusiform deposits of amyloid in familieswhopresentedclinicallywithgranu- (Ms Paliwal and Dr Sharma), the corneal stroma.4-6 larcornealdystrophyandherebyreporttheir and Cornea and Refractive Explicit mutations in TGFBI are re- clinical features with genetic analysis. Surgery Services, Dr Rajendra sponsible for specific types of 5q31- Prasad Centre for Ophthalmic linked corneal dystrophies, such as Groe- METHODS Sciences (Ms Gupta and nouw type I (R555W), Avellino (R124H), Dr Tandon), All India Institute Reis-Bücklers (R124L), Thiel-Behnke of Medical Sciences, New Delhi; 7 The study had the approval of the institute re- and Centre for Eye Research (R555Q), and lattice type I (R124C). The search ethics committee and conformed to the Australia, University of R124H mutation known to be associated tenets of the Declaration of Helsinki. Informed Melbourne, Melbourne, with Avellino corneal dystrophy (ACD) consent from all participants was obtained for Australia (Dr Vajpayee). (OMIM 121900) was initially described in slitlamp examination, in vivo white-light con-

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©2009 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 10/02/2021 focal microscopy (Confoscan 4; Nidek Technologies, Padova, with the following amplification conditions of 3 minutes of de- Italy), and molecular genetic studies. Detailed family history was naturation at 94°C followed by 35 cycles at 94°C for 1 minute, taken and the available family members were examined. 58°C for 1 minute and 72°C for 1 minute, and final extension was All members of both families were born in India and have given at 72°C for 5 minutes. their origin in the North Indian state of Haryana. They have Amplified products were sequenced directly with BigDye Ter- no relatives of Italian origin, making them the first Indian fami- minator Mix version 3.1 (Applied Biosystems, Foster City, Cali- lies, to our knowledge, to be reported to have ACD. The pedi- fornia), according to the manufacturer’s instructions, and then gree charts of the 2 families are shown in Figure 1. were analyzed on an ABI-3100 Genetic Analyzer (Applied Bio- Peripheral blood samples (5 mL) were collected in EDTA and systems). Nucleotide sequences for the coding regions were com- genomic DNA was extracted from all the samples. The DNA was pared with the nucleotide sequence of the published TGFBI hu- then subjected to polymerase chain reaction (PCR) amplifica- man complementary DNA (GenBank NM_000358). tion using a set of primer pairs, as described previously.7 The con- stituents and the conditions used for PCR reaction are described RESULTS herein. The 25-µL reaction mixture contained genomic DNA (200 ng), primers (0.5pM each), magnesium chloride (1.5mM), de- oxyribonucleotide triphosphate (0.2mM), 1ϫ PCR buffer (con- FAMILY A taining 10mM TRIS–hydrochloric acid, pH 8.3; 50mM potas- sium chloride; and 0.1% gelatin), and Taq polymerase (0.5 U; Case II-1 (proband) was first examined at the Cornea and Roche, Basel, Switzerland). The PCR machine was programmed External Eye Disease Clinic at the age of 51 years when he presented with visual disturbance. The patient’s best- corrected visual acuity on initial examination was 6/9 OU. Family A Slitlamp biomicroscopy showed discrete disc and ribbonlike opacities in the anterior stroma of the right eye I (Figure 2A and B) while the left eye (Figure 2E and F) was found to have predominantly ribbonlike discrete II opacities in the anterior stroma. The condition was diagnosed as granular corneal dystrophy. III Case III-2 (proband’s daughter) was referred to the Cor- nea and External Eye Disease Clinic at the age of 19 years when she complained of redness and watering. The pa- Family B tient’s unaided visual acuity was 6/6 OU. Slitlamp biomicroscopy revealed discrete ring- and crumb-shaped opaci- I ties distributed in a radiating pattern in the anterior stroma of both eyes (Figure 3), suggestive of granular corneal II dystrophy. In addition, she also had a few discrete, non- branching, linear, gray-white opacities in the anterior Female III Male stroma (Figure 3B and D). Examination of the unaffected Affected individual family members revealed a disease-free cornea. Affected individual IV FAMILY B Figure 1. Pedigrees of patients having R124H mutations in TGFBI, showing segregation of mutations, disease status of individuals, and individuals The second family was also clinically diagnosed as having examined (asterisks) in the 2 families A and B. Arrows indicate probands. granular corneal dystrophy and consisted of a 53-year-old

A B E F

C D G H

Figure 2. Slitlamp photographs of proband (case II-1, family A) showing symmetrical ribbonlike opacities in the anterior corneal stroma (right eye, A and B, left eye, E and F). Confocal images (right eye, C and D, left eye, G and H) showing hyperreflective focal deposits with irregular edges in the basal epithelium (C and G). Normal keratocyte nuclei are seen in the stroma (D and H).

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C D C D

Figure 3. Slitlamp photographs of the proband’s daughter (case III-2, family Figure 5. Slitlamp photographs of the proband’s daughter (case III-1, family A) showing axially distributed crumblike opacities in the right (A and B) and B). The right eye is more prominently affected (A and B). The gray-white left (C and D) eye. Arrows indicate the few gray-white, raylike, linear deposits linear deposits are indicated by the arrows (B and D). in the superficial stroma.

A B A B

Figure 6. Slitlamp photographs of the proband’s son (case III-2, family B). An isolated gray-white lesion is seen in the right eye (A) (white arrow). Also C D seen is a persistent pupillary membrane (yellow arrow). The left eye appeared normal (B).

R124H

80 90 100 CCCGG AAAAAAC G C GG G G CT G GG C

Figure 4. Slitlamp photographs of the proband (case II-1, family B) showing P1 a milder phenotype in the right (A and B) and left (C and D) eye. Arrows indicate faintly visible linear deposits. 80 90 100 CCCGGA C GGGGGGGGC AAAA CT A proband (case II-1), her 32-year-old daughter (case III-1), and a 28-year-old son (case III-2). Slitlamp examination of P2 the proband (case II-1) showed discrete rings, crumbs, and a few raylike, linear, gray-white opacities in the anterior axial 80 90 C GG A C CCGGGGC AAAAAGGG CT corneal stroma of both eyes, with more prominent clinical features in the right eye (Figure 4). The daughter (case C III-1) also had asymmetric involvement, the right eye Figure 5 GAAAAAACC GC C GG G G CTTTG GG CC G AAA G GG GGGG CCC GGC A G C TTTTTCCCCC AA CC G ( A and B) being more prominently affected, with -R----D-E-K-E-E--- T -L-M- R------G--GS -P -P-- - - -FI-F---A-- T-- - similar features as the mother but more pronounced. The son (case III-3) had a unilateral presentation with a single discrete opacity in the right eye (Figure 6A). Figure 7. Chromatogram showing R124H mutations in TGFBI of patients. Direct sequencing analysis of exon 4 of TGFBI in the 2 affected members from family A and the 3 affected members of family B revealed a single heterozygous missense COMMENT substitution at nucleotide position 418 (G to A) convert- ing arginine at codon 124 to histidine (Figure 7). This The families with ACD initially reported in the litera- mutation results in a change in the structure of the pro- ture were found to trace their ancestry to a large tein coded by TGFBI, resulting in hyaline and amyloid region of Campania in Italy comprising cities like deposition in the corneal stroma, and is known to be as- Naples, Avellino, Lioni, and Stio.8 Many cases of sociated with cases of ACD. Similar change at this posi- ACD have subsequently been reported from other tion was not seen in the unaffected members of both the countries.3,7,9-17 This study describes for the first time, families. to our knowledge, ACD from India in 2 families with

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©2009 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 10/02/2021 R124H mutation, thus emphasizing the geographic Author Contributions: Mss Paliwal and Gupta contrib- diversity of the disease. uted equally to this study. Avellino corneal dystrophy is an autosomal dominant Financial Disclosure: None reported. disorder, sharing its features with both granular and lat- Funding/Support: This work was supported by the De- tice corneal dystrophy, and results from a specific muta- partment of Biotechnology and the Council of Scientific tion (R124H) in TGFBI.7 In our study of the 5 affected in- and Industrial Research, Ministry of Science and Tech- dividuals, 3 individuals (family A case III-2 and family B nology, Government of India. cases II-1 and III-1) showed the presence of a few fine, gray- AdditionalContributions:MeenaVerma,BSc,tooktheclini- white linear deposits in the superficial stroma. These de- cal photographs and confocal images. We thank the patients posits were different from those classically seen in lattice and their family members for participating in this study. corneal dystrophy as these were not refractile, translu- cent, or branching in pattern. Two affected individuals in their sixth decade (family A case I-1 and family B case II-1) REFERENCES harbored the heterozygous R124H mutation but did not 1. Holland EJ, Daya SM, Stone EM, et al. Avellino corneal dystrophy: clinical mani- show any lattice lesions that are classically described with festations and natural history. Ophthalmology. 1992;99(10):1564-1568. progression of age in ACD. Confocal microscopy of 3 af- 2. Lucarelli MJ, Adamis AP. Avellino corneal dystrophy. Arch Ophthalmol. 1994;112 fected individuals (family A case II-1 and family B cases (3):418-419. II-1 and III-1) revealed highly reflective granular lesions 3. Rosenwasser GO, Sucheski BM, Rosa N, et al. Phenotypic variation in combined granular-lattice (Avellino) corneal dystrophy. 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