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Megalencephaly, autosomal dominant

MedGen UID:
812057
•Concept ID:
C3805727
•
Disease or Syndrome
Synonym: MEGALENCEPHALY, AUTOSOMAL DOMINANT
 
Monarch Initiative: MONDO:0007961
OMIM®: 155350

Definition

Primary megalencephaly is defined as a head circumference about the 98th percentile that most likely is due to brain enlargement and is not secondary to disease (review by Petersson et al., 1999). [from OMIM]

Clinical features

From HPO
Hydrocephalus
MedGen UID:
9335
•Concept ID:
C0020255
•
Disease or Syndrome
Hydrocephalus is an active distension of the ventricular system of the brain resulting from inadequate passage of CSF from its point of production within the cerebral ventricles to its point of absorption into the systemic circulation.
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Megalencephaly
MedGen UID:
65141
•Concept ID:
C0221355
•
Congenital Abnormality
Diffuse enlargement of the entire cerebral hemispheres leading to macrocephaly (with or without overlying cortical dysplasia).
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Intellectual disability
MedGen UID:
811461
•Concept ID:
C3714756
•
Mental or Behavioral Dysfunction
Intellectual disability, previously referred to as mental retardation, is characterized by subnormal intellectual functioning that occurs during the developmental period. It is defined by an IQ score below 70.
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Macrocephaly
MedGen UID:
745757
•Concept ID:
C2243051
•
Finding
Occipitofrontal (head) circumference greater than 97th centile compared to appropriate, age matched, sex-matched normal standards. Alternatively, a apparently increased size of the cranium.
See: Feature record | Search on this feature
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Recent clinical studies

Etiology

Identification of an NF1 Microdeletion with Optical Genome Mapping.
Büki G, Bekő A, Bödör C, Urbán P, Németh K, Hadzsiev K, Fekete G, Kehrer-Sawatzki H, Bene J
Int J Mol Sci 2023 Sep 1;24(17) doi: 10.3390/ijms241713580. PMID: 37686382Free PMC Article
Clinical and genetic diagnosis of Cowden syndrome: A case report of a rare PTEN germline variant and diverse clinical presentation.
Arai H, Akagi K, Nakagawa A, Onai Y, Utsu Y, Masuda S, Aotsuka N
Medicine (Baltimore) 2023 Jan 6;102(1):e32572. doi: 10.1097/MD.0000000000032572. PMID: 36607858Free PMC Article
Head circumference and anthropometric changes and their relation to plexiform and skin neurofibromas in sporadic and familial neurofibromatosis 1 Brazilian adults: a cross-sectional study.
Basto DL, de Souza Vieira G, Andrade-Losso RM, Almeida PN, Riccardi VM, Rozza-de-Menezes RE, Cunha KS
Orphanet J Rare Dis 2022 Sep 5;17(1):341. doi: 10.1186/s13023-022-02482-8. PMID: 36064430Free PMC Article
Clinical, radiological, and auxological characteristics of patients with cleidocranial dysplasia followed in a pediatric referral hospital in Argentina.
Ramos Mejía R, Rodríguez Celin M, Fano V
Arch Argent Pediatr 2018 Aug 1;116(4):e560-e566. doi: 10.5546/aap.2018.eng.e560. PMID: 30016033
Capillary malformations: a classification using specific names for specific skin disorders.
Happle R
J Eur Acad Dermatol Venereol 2015 Dec;29(12):2295-305. Epub 2015 Apr 10 doi: 10.1111/jdv.13147. PMID: 25864701

Diagnosis

Clinical and genetic diagnosis of Cowden syndrome: A case report of a rare PTEN germline variant and diverse clinical presentation.
Arai H, Akagi K, Nakagawa A, Onai Y, Utsu Y, Masuda S, Aotsuka N
Medicine (Baltimore) 2023 Jan 6;102(1):e32572. doi: 10.1097/MD.0000000000032572. PMID: 36607858Free PMC Article
2q37 deletion syndrome in a Colombian patient with macrocephaly: a case report.
Giraldo-Ocampo S, Pachajoa H
BMC Pediatr 2022 Oct 4;22(1):569. doi: 10.1186/s12887-022-03620-8. PMID: 36192675Free PMC Article
O'Donnell-Luria-Rodan syndrome: description of a second multinational cohort and refinement of the phenotypic spectrum.
Velmans C, O'Donnell-Luria AH, Argilli E, Tran Mau-Them F, Vitobello A, Chan MC, Fung JL, Rech M, Abicht A, Aubert Mucca M, Carmichael J, Chassaing N, Clark R, Coubes C, Denommé-Pichon AS, de Dios JK, England E, Funalot B, Gerard M, Joseph M, Kennedy C, Kumps C, Willems M, van de Laar IMBH, Aarts-Tesselaar C, van Slegtenhorst M, Lehalle D, Leppig K, Lessmeier L, Pais LS, Paterson H, Ramanathan S, Rodan LH, Superti-Furga A, Chung BHY, Sherr E, Netzer C, Schaaf CP, Erger F
J Med Genet 2022 Jul;59(7):697-705. Epub 2021 Jul 28 doi: 10.1136/jmedgenet-2020-107470. PMID: 34321323Free PMC Article
Novel loss-of-function variants in TRIO are associated with neurodevelopmental disorder: case report.
Schultz-Rogers L, Muthusamy K, Pinto E Vairo F, Klee EW, Lanpher B
BMC Med Genet 2020 Nov 10;21(1):219. doi: 10.1186/s12881-020-01159-y. PMID: 33167890Free PMC Article
Clinical, radiological, and auxological characteristics of patients with cleidocranial dysplasia followed in a pediatric referral hospital in Argentina.
Ramos Mejía R, Rodríguez Celin M, Fano V
Arch Argent Pediatr 2018 Aug 1;116(4):e560-e566. doi: 10.5546/aap.2018.eng.e560. PMID: 30016033

Therapy

Clinical and functional studies of MTOR variants in Smith-Kingsmore syndrome reveal deficits of circadian rhythm and sleep-wake behavior.
Liu AC, Shen Y, Serbinski CR, He H, Roman D, Endale M, Aschbacher-Smith L, King KA, Granadillo JL, López I, Krueger DA, Dye TJ, Smith DF, Hogenesch JB, Prada CE
HGG Adv 2024 Oct 10;5(4):100333. Epub 2024 Jul 17 doi: 10.1016/j.xhgg.2024.100333. PMID: 39030910Free PMC Article
Hemimegalencephaly and tuberous sclerosis complex: A rare yet challenging association.
Sidira C, Vargiami E, Dragoumi P, Zafeiriou DI
Eur J Paediatr Neurol 2021 Jan;30:58-65. Epub 2020 Dec 23 doi: 10.1016/j.ejpn.2020.12.007. PMID: 33387903
Dominantly inherited megalencephaly, muscle weakness, and myoliposis: a carnitine-deficient myopathy within the spectrum of the Ruvalcaba-Myhre-Smith syndrome.
Powell BR, Budden SS, Buist NR
J Pediatr 1993 Jul;123(1):70-5. doi: 10.1016/s0022-3476(05)81539-2. PMID: 8320628

Prognosis

Insights From a Novel Splicing Variant and Recurrent Arginine Variants in the CHD3 Gene Causing Snijders Blok-Campeau Syndrome.
Tie X, Che F, Liu S, Mo L, Zhang L, Li B, Yang Y
Am J Med Genet A 2025 Mar;197(3):e63930. Epub 2024 Nov 14 doi: 10.1002/ajmg.a.63930. PMID: 39542866
A New De Novo Missense Variant of the TET3 Gene in a Patient with Epilepsy and Macrocephaly.
Foti MRS, Tedesco MG, Colavito D, Rogaia D, Mencarelli A, Schippa M, Gradassi C, Romani R, Ardisia C, Prontera P
Int J Mol Sci 2024 Sep 6;25(17) doi: 10.3390/ijms25179676. PMID: 39273623Free PMC Article
An in-frame deletion affecting the critical acid loop of PPP2R5D is associated with a neonatal lethal form of PPP2R5D-related neurodevelopmental disorder.
Alhajaj G, Lacroix C, Trakadis Y, Garfinkle J, Srour M
Am J Med Genet A 2023 Sep;191(9):2416-2421. Epub 2023 May 30 doi: 10.1002/ajmg.a.63307. PMID: 37248744
G syndrome: an unusual family.
Allanson JE
Am J Med Genet 1988 Nov;31(3):637-42. doi: 10.1002/ajmg.1320310319. PMID: 3228142

Clinical prediction guides

A New De Novo Missense Variant of the TET3 Gene in a Patient with Epilepsy and Macrocephaly.
Foti MRS, Tedesco MG, Colavito D, Rogaia D, Mencarelli A, Schippa M, Gradassi C, Romani R, Ardisia C, Prontera P
Int J Mol Sci 2024 Sep 6;25(17) doi: 10.3390/ijms25179676. PMID: 39273623Free PMC Article
O'Donnell-Luria-Rodan syndrome: description of a second multinational cohort and refinement of the phenotypic spectrum.
Velmans C, O'Donnell-Luria AH, Argilli E, Tran Mau-Them F, Vitobello A, Chan MC, Fung JL, Rech M, Abicht A, Aubert Mucca M, Carmichael J, Chassaing N, Clark R, Coubes C, Denommé-Pichon AS, de Dios JK, England E, Funalot B, Gerard M, Joseph M, Kennedy C, Kumps C, Willems M, van de Laar IMBH, Aarts-Tesselaar C, van Slegtenhorst M, Lehalle D, Leppig K, Lessmeier L, Pais LS, Paterson H, Ramanathan S, Rodan LH, Superti-Furga A, Chung BHY, Sherr E, Netzer C, Schaaf CP, Erger F
J Med Genet 2022 Jul;59(7):697-705. Epub 2021 Jul 28 doi: 10.1136/jmedgenet-2020-107470. PMID: 34321323Free PMC Article
Hypoglycemia due to PI3K/AKT/mTOR signaling pathway defects: two novel cases and review of the literature.
Maines E, Franceschi R, Martinelli D, Soli F, Lepri FR, Piccoli G, Soffiati M
Hormones (Athens) 2021 Dec;20(4):623-640. Epub 2021 Apr 20 doi: 10.1007/s42000-021-00287-1. PMID: 33876391
Clinical, radiological, and auxological characteristics of patients with cleidocranial dysplasia followed in a pediatric referral hospital in Argentina.
Ramos Mejía R, Rodríguez Celin M, Fano V
Arch Argent Pediatr 2018 Aug 1;116(4):e560-e566. doi: 10.5546/aap.2018.eng.e560. PMID: 30016033
Localization of the gene for Cowden disease to chromosome 10q22-23.
Nelen MR, Padberg GW, Peeters EA, Lin AY, van den Helm B, Frants RR, Coulon V, Goldstein AM, van Reen MM, Easton DF, Eeles RA, Hodgsen S, Mulvihill JJ, Murday VA, Tucker MA, Mariman EC, Starink TM, Ponder BA, Ropers HH, Kremer H, Longy M, Eng C
Nat Genet 1996 May;13(1):114-6. doi: 10.1038/ng0596-114. PMID: 8673088

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