X-linked inheritance in neuronal migration disorders (NMD)
- McGill Univ., Montreal (Canada); and others
With the advent of MRI imaging, an increasing number of NMD have been identified in patients with epilepsy. Although most cases have been sporadic, families with these disorders have now been reported in several types of NMD. Furthermore, subcortical bank heterotopia (SBH) or {open_quotes}double cortex syndrome{close_quotes} and periventricular nodular heterotopia (PNH) have a marked female predominance. Two females with SBH, mild mental retardation and seizures had sons with lissencephaly, severe retardation and seizures, and daughters with SBH. X-linked lissencephaly has been observed in several other families, and one girl with lissencephaly was found to have a de novo X-autosomal translocation with a breakpoint in chromosome Xq22. We have studied three families with two or more generations affected by PNH in females, a high frequency of spontaneous abortions and abnormal sex ratios in sibships. The clinical manifestations include seizures and normal intelligence. Three other families with PNH in females have been reported in the literature. Bilateral perisylvian polymicrogyria has been reported in monozygotic twins and in siblings, and we have studied a brother and sister with an affected maternal uncle. These findings suggest sex-linked dominant inheritance with male lethality or severe expression in males. The three disorders described above may represent different mutations of a single gene or mutations in two or more genes on the X-chromosome. At least one gene is probably located in chromosome band Xq22. Genetic linkage studies in families with NMD as well as a search for candidate genes such as adhesion molecules known to map on the X-chromosome should lead to the identification of the gene(s) responsible for these disorders.
- OSTI ID:
- 133410
- Report Number(s):
- CONF-941009-; ISSN 0002-9297; TRN: 95:005313-0138
- Journal Information:
- American Journal of Human Genetics, Vol. 55, Issue Suppl.3; Conference: 44. annual meeting of the American Society of Human Genetics, Montreal (Canada), 18-22 Oct 1994; Other Information: PBD: Sep 1994
- Country of Publication:
- United States
- Language:
- English
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