DOCSLIB.ORG

Developmental Disabilities Handbook

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

Developmental Disabilities handbook A University Center for Excellence in Developmental Disabilities Education, Research and Service The Developmental Disabilities Handbook is a product of the Center for Disabilities, Department of Pediatrics, The University of South Dakota School of Medicine and may not be reproduced without permission. The information contained in the Developmental Disabilities Handbook is meant to provide general information. It is not meant to act as a diagnostic tool or to act as a comprehensive description of developmental disabilities in general or of specific developmental disabilities. To request permission contact: Director of Information and Resources Center for Disabilities Department of Pediatrics The University of South Dakota School of Medicine 1400 West 22nd Street Sioux Falls, South Dakota 57105 (605) 357-1439 1-800-658-3080 (Voice/TTY) On the web - http://www.usd.edu/cd To receive this product in an alternative format, please contact the above. This handbook is sponsored in part by a grant from: South Dakota Council on Developmental Disabilities Spring 2003 Table of contents Legal Definitions ...................................................................................................................... 1 Adrenoleukodystrophy............................................................................................................... 2 Angelman Syndrome ................................................................................................................. 3 Apert Syndrome....................................................................................................................... 4 Arthrogryposis ........................................................................................................................ 5 Asperger’s Syndrome ................................................................................................................ 6 Attention-Deficit/Hyperactivity Disorder ....................................................................................... 7 Autism .................................................................................................................................. 8 Autism Spectrum Disorders......................................................................................................... 9 Becker Muscular Dystrophy........................................................................................................10 Beckwith-Wiedemann Syndrome .................................................................................................11 Cerebral Palsy ........................................................................................................................12 Charcot-Marie-Tooth ...............................................................................................................13 Childhood Disintegrative Disorder ...............................................................................................14 Cleft Lip and/or Cleft Palate ......................................................................................................15 Coffin-Lowry Syndrome............................................................................................................16 Congenital Hypothyroidism........................................................................................................17 Cornelia de Lange Syndrome ......................................................................................................18 Cri du Chat Syndrome ..............................................................................................................19 Cystic Fibrosis ........................................................................................................................20 Down Syndrome .....................................................................................................................21 Duchenne Muscular Dystrophy....................................................................................................22 Epilepsy................................................................................................................................23 Fetal Alcohol Spectrum Disorders ................................................................................................24 Fragile X Syndrome .................................................................................................................25 Goldenhar Syndrome................................................................................................................26 Krabbe Disease .......................................................................................................................27 Klinefelter Syndrome ...............................................................................................................28 Learning Disabilities.................................................................................................................29 Leukodystrophy ......................................................................................................................30 Table of contents Marfan Syndrome....................................................................................................................31 Metachromatic Leukodystrophy...................................................................................................32 Mental Retardation ..................................................................................................................33 Mucopolysaccharidosis (MPS) .....................................................................................................34 MPS I - Hurler Syndrome, Scheie Syndrome, Hurler-Scheie Syndrome ...................................................35 MPS II - Hunter Syndrome.........................................................................................................36 MPS III - San Filippo Syndrome ...................................................................................................37 MPS IV - Morquio Syndrome .....................................................................................................38 MPS VI - Maroteaux-Lamy Syndrome ...........................................................................................39 MPS VII - Sly Syndrome ............................................................................................................40 Neurofibromatosis...................................................................................................................41 Neuronal Cefoid Lipofuscinoses - Batten Disease ..............................................................................42 Noonan Syndrome...................................................................................................................43 Pervasive Developmental Disorder - Not Otherwise Specified..............................................................44 Phenylketonuria......................................................................................................................45 Prader-Willi Syndrome .............................................................................................................46 Rett Syndrome .......................................................................................................................47 Spina Bifida............................................................................................................................48 Spinal Muscular Atrophy ...........................................................................................................49 Tourette Syndrome..................................................................................................................50 Traumatic Brain Injury..............................................................................................................51 Tuberous Sclerosis...................................................................................................................52 Turner Syndrome....................................................................................................................53 Williams Syndrome..................................................................................................................54 Zellweger Syndrome ................................................................................................................55 Overview of ADA, IDEA and Section 504 ..................................................................................56-58 Selected Resources ..............................................................................................................59-66 Glossary ...........................................................................................................................67-71 Bibliography ......................................................................................................................72-77 legal definitions United States Federal Definition - from The Developmental Disabilities Assistance and Bill of Rights Act Amendments of 1994 Public Law 103-230 [42 USC 6001] (8) Developmental Disability The term “developmental disability” means a severe, chronic disability of an individual 5 years of age or older that: (A) is attributable to a mental or physical impairment or combination of mental and physical impairments; (B) is manifested before the individual attains age 22; (C) is likely to continue indefinitely; (D) results in substantial functional limitations
Recommended publications

  • Basic Concepts in Basic Concepts in Dysmorphology

    Basic Concepts in Dysmorphology Samia Temtamy* & Mona Aglan** *Professor of Human Genetics **Professor of Clinical Genetics Human Genetics & Genome Research Division National Research Centre, Cairo, Egypt OtliOutline y Definition of dysmorphology y Definition of terms routinely used in the description of birth defects y Impact of malformations y The difference between major & minor anomalies y Approach to a dysmorphic individual: y Suspicion & analysis y Systematic physical examination y CfitifdiConfirmation of diagnos is y Intervention y Summary 2 DfiitiDefinition of fd dysmorph hlology y The term “dysmorphology” was first coined by Dr. DidSithUSAiDavid Smith, USA in 1960s. y It implies study of human congenital defects and abnormalities of body structure that originate before birth. y The term “dysmorphic” is used to describe individuals whose physical fffeatures are not usually found in other individuals with the same age or ethnic background. y “Dys” (Greek)=disordered or abnormal and “Morph”=shape 3 Definition of terms routinely used in the d escri pti on of bi rth d ef ect s y A malformation / anomaly: is a primary defect where there i s a bas ic a ltera tion o f s truc ture, usuall y occurring before 10 weeks of gestation. y Examples: cleft palate, anencephaly, agenesis of limb or part of a limb. 4 Cleft lip & palate Absence of digits (ectrodactyly) y Malformation Sequence: A pattern of multiple defects resulting from a single primary malformation. y For example: talipes and hydrocephalus can result from a lumbar neural tube defect. Lumbar myelomeningeocele 5 y Malformation Syndrome: A pattern of features, often with an underlying cause, that arises from several different errors in morphogenesis.
  • Dysmorphology Dysmorphism

    Dysmorphology Dysmorphism

    Dysmorphology Carolyn Jones, M.D., PhD Dysmorphism Morphologic developmental abnormalities. This may been seen in many syndromes of genetic or environmental origin. 1 Malformation A recognized dysmorphic feature. A structure not formed correctly. This can either be the cause of genetic factors or environment. 2 Deformation An external force resulting in the inability of a structure to form correctly. Example: club feet in a woman with oligohydramnios, fibroid tumors or multiple gestation. Disruption Birth defect resulting from the destruction of a normally forming structure. This can be caused by vascular occlusion, teratogen, or rupture of amniotic sac (amniotic band syndrome). 3 Common Dysmorphic features Wide spacing between eyes, hypertelorism Narrow spacing between eyes, hypotelorism Palpebral fissure length Epicanthal folds Common Dysmorphic Features Philtrum length Upper lip Shape of nose 4 Syndrome A number of malformations seen together Cause of Syndromes Chromosomal aneuploidy Single Gene abnormalities Teratogen exposure Environmental 5 Chromosomal Aneuploidy Nondisjuction resulting in the addition or loss of an entire chromosome Deletion of a part of a chromosome Microdeletion syndromes (small piece missing which is usually only detected using special techniques) 6 Common Chromosomal Syndromes caused by Nondisjuction Down syndrome (trisomy 21) Patau syndrome (trisomy 13) Edwards syndrome (trisomy 18) Turner syndrome (monosomy X) Klinefelter syndrome (47,XXY) Clinical Features at birth of Down syndrome Low set small ears Hypotonia Simian crease Wide space between first and second toe Flat face 7 Clinical Features of Down Syndrome Small stature Congenital heart defects (50-70%) Acquired and congenital hearing impairment. Duodenal atresia Hirshprungs disease Trisomy 13 Occurs in 1/5000 live births.
  • Segmental Overvekst Og Vaskulærmalformasjoner V02

    Segmental Overvekst Og Vaskulærmalformasjoner V02

    2/1/2021 Segmental overvekst og vaskulærmalformasjoner v02 Avdeling for medisinsk genetikk Segmental overvekst og vaskulærmalformasjoner Genpanel, versjon v02 * Enkelte genomiske regioner har lav eller ingen sekvensdekning ved eksomsekvensering. Dette skyldes at de har stor likhet med andre områder i genomet, slik at spesifikk gjenkjennelse av disse områdene og påvisning av varianter i disse områdene, blir vanskelig og upålitelig. Disse genetiske regionene har vi identifisert ved å benytte USCS segmental duplication hvor områder større enn 1 kb og ≥90% likhet med andre regioner i genomet, gjenkjennes (https://genome.ucsc.edu). Vi gjør oppmerksom på at ved identifiseringav ekson oppstrøms for startkodon kan eksonnummereringen endres uten at transkript ID endres. Avdelingens websider har en full oversikt over områder som er affisert av segmentale duplikasjoner. ** Transkriptets kodende ekson. Ekson Gen Gen affisert (HGNC (HGNC Transkript Ekson** Fenotype av symbol) ID) segdup* ACVRL1 175 NM_000020.3 2-10 Telangiectasia, hereditary hemorrhagic, type 2 OMIM ADAMTS3 219 NM_014243.3 1-22 Hennekam lymphangiectasia- lymphedema syndrome 3 OMIM AKT1 391 NM_005163.2 2-14 Cowden syndrome 6 OMIM Proteus syndrome, somatic OMIM AKT2 392 NM_001626.6 2-14 Diabetes mellitus, type II OMIM Hypoinsulinemic hypoglycemia with hemihypertrophy OMIM AKT3 393 NM_005465.7 2-14 Megalencephaly-polymicrogyria- polydactyly-hydrocephalus syndrome 2 OMIM file:///data/SegOv_v02-web.html 1/7 2/1/2021 Segmental overvekst og vaskulærmalformasjoner v02 Ekson Gen Gen affisert (HGNC (HGNC
  • An Overview of Lesch-Nyhan Syndrome

    An Overview of Lesch-Nyhan Syndrome

    An Overview of Lesch-Nyhan Syndrome Abstract Lesch-Nyhan Syndrome is a disorder that strikes the sufferer with debilitating motor and cognitive problems, hyperuricemia, and the urge to do harm to yourself with acts of self-injurious behavior. Research has lead to the discovery of a genetic sequence that results in a defective enzyme, but researchers are still unsure how this leads to the neurological and behavioral problems that are the hallmark of the disorder. Treatments as simple as wearing oven mitts and as complicated as electrical wiring in the brain have been used to help LNS patients, but no cure for the syndrome seems in sight. Lars Sorensen Prof. Stanley Vitello : IDD : 293:522 : Fall 2008 Rutgers University - Graduate School of Education Introduction In the world of developmental and physical disorders none is stranger than Lesch-Nyhan Syndrome. It brings with it a variety of physical ailments but the defining feature of the condition is behavioral. The sufferer seems to be overtaken with an involuntary uncontrollable compulsion to destroy themselves and those around them. In the autumn of 1962, a young mother brought her four year old son to the pediatric emergency room at Johns Hopkins medical center. The boy had previously been diagnosed with cerebral palsy and could not walk or sit up. He was experiencing pain when he urinated. His mother told the resident who was examining the boy that he had “sand in his diaper” (Preston, 2007). The young boy was admitted to the hospital. The resident and an intern began examining the “sand” from the boy's diaper.
  • (Hunter Syndrome) Complicated by Autoimmune Hemolytic Anemia

    (Hunter Syndrome) Complicated by Autoimmune Hemolytic Anemia

    Bone Marrow Transplantation (2000) 25, 1093–1099 2000 Macmillan Publishers Ltd All rights reserved 0268–3369/00 $15.00 www.nature.com/bmt Case report Unrelated umbilical cord blood transplantation in infancy for mucopolysaccharidosis type IIB (Hunter syndrome) complicated by autoimmune hemolytic anemia CA Mullen1,2, JN Thompson3, LA Richard and KW Chan1 Departments of 1Pediatrics and 2Immunology, University of Texas MD Anderson Cancer Center, Houston, Texas; 3Laboratory of Medical Genetics, University of Alabama at Birmingham, Birmingham, Alabama, USA Summary: a median of 21 years in type IIB.8 Allogeneic BMT has been used to treat Hunter disease, but remains controversial This report describes unrelated umbilical cord blood since it often fails to reverse CNS impairment9–11 and car- transplantation for a 10-month-old infant boy with ries with it substantial early mortality and morbidity. Here, mucopolysaccharidosis IIB (Hunter syndrome), an X- we report treatment of an infant with mucopolysacch- linked metabolic storage disorder due to deficiency of arisosis type IIB with transplantation of unrelated umbilical iduronate sulfatase. Two years after transplant ෂ55% cord blood cells and its complication by autoimmune hemo- normal plasma enzyme activity has been restored and lytic anemia. abnormal urinary excretion of glycosaminoglycans has nearly completely resolved. The boy has exhibited nor- mal growth and development after transplant. Nine Case report months after transplant he developed severe auto- immune hemolytic anemia and required 14 months of The patient is the only child of a couple with a maternal corticosteroid treatment to prevent clinically significant family history of Hunter syndrome. The mother’s brother anemia. Bone marrow transplantation for Hunter syn- was diagnosed with Hunter syndrome in 1979 at age 3 years drome and post-transplant hemolytic anemia are when he exhibited the physical stigmata of the disorder.
  • Adult Onset) an Information Sheet for the Person Who Has Been Diagnosed with a Leukodystrophy, Their Family, and Friends

    Adult Onset) an Information Sheet for the Person Who Has Been Diagnosed with a Leukodystrophy, Their Family, and Friends

    Leukodystrophy (Adult Onset) An information sheet for the person who has been diagnosed with a leukodystrophy, their family, and friends. ‘Leukodystrophy’ and the related term ‘leukoencephalopathy’ The person may notice they trip more easily, particularly on refer to a group of conditions that affect the myelin, or white uneven ground or steps. matter, of the brain and spinal cord. Other symptoms that people with adult-onset Leukodystrophies are neurological, degenerative disorders, leukodystrophy may experience include: sensitivity to and most are genetic. This means that a person’s condition extremes of temperature, such as difficulty tolerating hot is caused by a change to one of the genes that are involved summer weather; pain or abnormal sensation, particularly in in the development of myelin, leading to deterioration in the legs; shaking or tremors; loss of vision and/or hearing; many of the body’s neurological functions. The pattern headaches, and difficulty with coordination. of symptoms varies from one type of leukodystrophy to People with leukodystrophy often experience long delays another, and there may even be some variation between before receiving a correct diagnosis. This is partly because different people with the same condition, however all are the symptoms can be quite vague and associated with described as progressive. This means that although there many different disorders. Leukodystrophies are rare, and may be periods of stability, the condition doesn’t go into it is routine medical practice to rule out more common and ‘remission’ as may be seen in some other neurological treatable causes before testing for rarer conditions. There conditions, and over time the condition worsens.
  • Child Neurology: Hereditary Spastic Paraplegia in Children S.T

    Child Neurology: Hereditary Spastic Paraplegia in Children S.T

    RESIDENT & FELLOW SECTION Child Neurology: Section Editor Hereditary spastic paraplegia in children Mitchell S.V. Elkind, MD, MS S.T. de Bot, MD Because the medical literature on hereditary spastic clinical feature is progressive lower limb spasticity B.P.C. van de paraplegia (HSP) is dominated by descriptions of secondary to pyramidal tract dysfunction. HSP is Warrenburg, MD, adult case series, there is less emphasis on the genetic classified as pure if neurologic signs are limited to the PhD evaluation in suspected pediatric cases of HSP. The lower limbs (although urinary urgency and mild im- H.P.H. Kremer, differential diagnosis of progressive spastic paraplegia pairment of vibration perception in the distal lower MD, PhD strongly depends on the age at onset, as well as the ac- extremities may occur). In contrast, complicated M.A.A.P. Willemsen, companying clinical features, possible abnormalities on forms of HSP display additional neurologic and MRI abnormalities such as ataxia, more significant periph- MD, PhD MRI, and family history. In order to develop a rational eral neuropathy, mental retardation, or a thin corpus diagnostic strategy for pediatric HSP cases, we per- callosum. HSP may be inherited as an autosomal formed a literature search focusing on presenting signs Address correspondence and dominant, autosomal recessive, or X-linked disease. reprint requests to Dr. S.T. de and symptoms, age at onset, and genotype. We present Over 40 loci and nearly 20 genes have already been Bot, Radboud University a case of a young boy with a REEP1 (SPG31) mutation. Nijmegen Medical Centre, identified.1 Autosomal dominant transmission is ob- Department of Neurology, PO served in 70% to 80% of all cases and typically re- Box 9101, 6500 HB, Nijmegen, CASE REPORT A 4-year-old boy presented with 2 the Netherlands progressive walking difficulties from the time he sults in pure HSP.
  • Mini-Review on “Molecular Diagnosis of 65 Families With

    Mini-Review on “Molecular Diagnosis of 65 Families With

    Mashima R, Okuyama T. J Rare Dis Res Treat. (2016) 2(1): 43-46 Journal of www.rarediseasesjournal.com Rare Diseases Research & Treatment Mini-Review Open Access Mini-review on “Molecular diagnosis of 65 families with mucopoly- saccharidosis type II (Hunter syndrome) characterized by 16 novel mutations in the IDS gene: Genetic, pathological, and structural stud- ies on iduronate-2-sulfatase.” Ryuichi Mashima1* and Torayuki Okuyama1,2 1Department of Clinical Laboratory Medicine, National Center for Child Health and Development, 2-10-1 Okura, Setagaya-ku, Tokyo 157-8535, Japan 2Center for Lysosomal Storage Disorders, National Center for Child Health and Development, 2-10-1 Okura, Setagaya-ku, Tokyo 157-8535, Japan ABSTRACT Article Info Article Notes Mucopolysaccharidosis type II (MPS II; Hunter syndrome; OMIM #309900) Received: November 29, 2016 is an X-linked congenital disorder characterized by an accumulation of Accepted: December 28, 2016 glycosaminoglycans in the body. Accumulating evidence has suggested that the prevalence of the severe type of MPS II is almost 70%. In addition, novel *Correspondence: mutations that are relevant to MPS II pathogenesis are being increasingly Ryuichi Mashima, Department of Clinical Laboratory Medicine, National Center for Child Health and Development, 2-10- discovered, so the databases of genetic data regarding pathogenic mutations 1 Okura, Setagaya-ku, Tokyo 157-8535, Japan, E-mail: have been growing. We have recently reported a collection of 16 novel [email protected] pathogenic mutations of the iduronate-2-sulfatase (IDS) gene in 65 families with MPS II in a Japanese population1. We also proposed that a homology- © 2016 Ryuichi Mashima.
  • Hereditary Spastic Paraparesis: a Review of New Developments

    Hereditary Spastic Paraparesis: a Review of New Developments

    J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.69.2.150 on 1 August 2000. Downloaded from 150 J Neurol Neurosurg Psychiatry 2000;69:150–160 REVIEW Hereditary spastic paraparesis: a review of new developments CJ McDermott, K White, K Bushby, PJ Shaw Hereditary spastic paraparesis (HSP) or the reditary spastic paraparesis will no doubt Strümpell-Lorrain syndrome is the name given provide a more useful and relevant classifi- to a heterogeneous group of inherited disorders cation. in which the main clinical feature is progressive lower limb spasticity. Before the advent of Epidemiology molecular genetic studies into these disorders, The prevalence of HSP varies in diVerent several classifications had been proposed, studies. Such variation is probably due to a based on the mode of inheritance, the age of combination of diVering diagnostic criteria, onset of symptoms, and the presence or other- variable epidemiological methodology, and wise of additional clinical features. Families geographical factors. Some studies in which with autosomal dominant, autosomal recessive, similar criteria and methods were employed and X-linked inheritance have been described. found the prevalance of HSP/100 000 to be 2.7 in Molise Italy, 4.3 in Valle d’Aosta Italy, and 10–12 Historical aspects 2.0 in Portugal. These studies employed the In 1880 Strümpell published what is consid- diagnostic criteria suggested by Harding and ered to be the first clear description of HSP.He utilised all health institutions and various reported a family in which two brothers were health care professionals in ascertaining cases aVected by spastic paraplegia. The father was from the specific region.
  • 2018 Etiologies by Frequencies

    2018 Etiologies by Frequencies

    2018 Etiologies in Order of Frequency by Category Hereditary Syndromes and Disorders Count CHARGE Syndrome 958 Down syndrome (Trisomy 21 syndrome) 308 Usher I syndrome 252 Stickler syndrome 130 Dandy Walker syndrome 119 Cornelia de Lange 102 Goldenhar syndrome 98 Usher II syndrome 83 Wolf-Hirschhorn syndrome (Trisomy 4p) 68 Trisomy 13 (Trisomy 13-15, Patau syndrome) 60 Pierre-Robin syndrome 57 Moebius syndrome 55 Trisomy 18 (Edwards syndrome) 52 Norrie disease 38 Leber congenital amaurosis 35 Chromosome 18, Ring 18 31 Aicardi syndrome 29 Alstrom syndrome 27 Pfieffer syndrome 27 Treacher Collins syndrome 27 Waardenburg syndrome 27 Marshall syndrome 25 Refsum syndrome 21 Cri du chat syndrome (Chromosome 5p- synd) 16 Bardet-Biedl syndrome (Laurence Moon-Biedl) 15 Hurler syndrome (MPS I-H) 15 Crouzon syndrome (Craniofacial Dysotosis) 13 NF1 - Neurofibromatosis (von Recklinghausen dis) 13 Kniest Dysplasia 12 Turner syndrome 11 Usher III syndrome 10 Cockayne syndrome 9 Apert syndrome/Acrocephalosyndactyly, Type 1 8 Leigh Disease 8 Alport syndrome 6 Monosomy 10p 6 NF2 - Bilateral Acoustic Neurofibromatosis 6 Batten disease 5 Kearns-Sayre syndrome 5 Klippel-Feil sequence 5 Hereditary Syndromes and Disorders Count Prader-Willi 5 Sturge-Weber syndrome 5 Marfan syndrome 3 Hand-Schuller-Christian (Histiocytosis X) 2 Hunter Syndrome (MPS II) 2 Maroteaux-Lamy syndrome (MPS VI) 2 Morquio syndrome (MPS IV-B) 2 Optico-Cochleo-Dentate Degeneration 2 Smith-Lemli-Opitz (SLO) syndrome 2 Wildervanck syndrome 2 Herpes-Zoster (or Hunt) 1 Vogt-Koyanagi-Harada
  • Phenotypic and Genotypic Characterisation of Noonan-Like

    Phenotypic and Genotypic Characterisation of Noonan-Like

    1of5 ELECTRONIC LETTER J Med Genet: first published as 10.1136/jmg.2004.024091 on 2 February 2005. Downloaded from Phenotypic and genotypic characterisation of Noonan-like/ multiple giant cell lesion syndrome J S Lee, M Tartaglia, B D Gelb, K Fridrich, S Sachs, C A Stratakis, M Muenke, P G Robey, M T Collins, A Slavotinek ............................................................................................................................... J Med Genet 2005;42:e11 (http://www.jmedgenet.com/cgi/content/full/42/2/e11). doi: 10.1136/jmg.2004.024091 oonan-like/multiple giant cell lesion syndrome (NL/ MGCLS; OMIM 163955) is a rare condition1–3 with Key points Nphenotypic overlap with Noonan’s syndrome (OMIM 163950) and cherubism (OMIM 118400) (table 1). N Noonan-like/multiple giant cell lesion syndrome (NL/ Recently, missense mutations in the PTPN11 gene on MGCLS) has clinical similarities with Noonan’s syn- chromosome 12q24.1 have been identified as the cause of drome and cherubism. It is unclear whether it is a Noonan’s syndrome in 45% of familial and sporadic cases,45 distinct entity or a variant of Noonan’s syndrome or indicating genetic heterogeneity within the syndrome. In the cherubism. 5 study by Tartaglia et al, there was a family in which three N Three unrelated patients with NL/MGCLS were char- members had features of Noonan’s syndrome; two of these acterised, two of whom were found to have mutations had incidental mandibular giant cell lesions.3 All three in the PTPN11 gene, the mutation found in 45% of members were found to have a PTPN11 mutation known to patients with Noonan’s syndrome.
  • Megalencephaly and Macrocephaly

    Megalencephaly and Macrocephaly

    277 Megalencephaly and Macrocephaly KellenD.Winden,MD,PhD1 Christopher J. Yuskaitis, MD, PhD1 Annapurna Poduri, MD, MPH2 1 Department of Neurology, Boston Children’s Hospital, Boston, Address for correspondence Annapurna Poduri, Epilepsy Genetics Massachusetts Program, Division of Epilepsy and Clinical Electrophysiology, 2 Epilepsy Genetics Program, Division of Epilepsy and Clinical Department of Neurology, Fegan 9, Boston Children’s Hospital, 300 Electrophysiology, Department of Neurology, Boston Children’s Longwood Avenue, Boston, MA 02115 Hospital, Boston, Massachusetts (e-mail: [email protected]). Semin Neurol 2015;35:277–287. Abstract Megalencephaly is a developmental disorder characterized by brain overgrowth secondary to increased size and/or numbers of neurons and glia. These disorders can be divided into metabolic and developmental categories based on their molecular etiologies. Metabolic megalencephalies are mostly caused by genetic defects in cellular metabolism, whereas developmental megalencephalies have recently been shown to be caused by alterations in signaling pathways that regulate neuronal replication, growth, and migration. These disorders often lead to epilepsy, developmental disabilities, and Keywords behavioral problems; specific disorders have associations with overgrowth or abnor- ► megalencephaly malities in other tissues. The molecular underpinnings of many of these disorders are ► hemimegalencephaly now understood, providing insight into how dysregulation of critical pathways leads to ►