Variability of the recessive oculopharyngeal muscular dystrophy phenotype.

Abstract

Oculopharyngeal muscular dystrophy (OPMD) is usually transmitted as an autosomal-dominant trait and characterized by an expansion from 6 to 8 or more GCG/GCA repeats in the poly-(A) binding protein nuclear 1 (PABPN1) gene on chromosome 14q11. Autosomal-recessive OPMD with a homozygous (GCG)7 expansion of PABPN1 has only been described in two Canadian patients, who showed a comparably mild phenotype, suggesting that it is less severe than the dominant form. We clinically and genetically characterized the first two reported cases of autosomal-recessive OPMD in Europe. Remarkably, both patients revealed severe and diverse phenotypes, with an unusual onset and atypical clinical course in one patient. Former studies found a 1%-2% frequency of the (GCG)7 allele, which theoretically produces an incidence of 1:10,000 of autosomal-recessive OPMD in the general population. We conclude that the apparent rarity of the autosomal-recessive form of OPMD may be due to the fact that genetic testing is generally administered only to patients with typical clinical features or a positive family history.

• Authors: Alexander Semmler, Wolfram Kress, Stefan Vielhaber, Rolf Schröder, Cornelia Kornblum
• Journal: Muscle & nerve (Muscle Nerve) Vol. 35 Issue 5 Pg. 681-4 (May 2007) ISSN: 0148-639X [Print] United States
• PMID: 17206657 (Publication Type: Case Reports, Journal Article)

Chemical References

• Poly(A)-Binding Protein I

Topics

• Aged
• Alleles
• Chromosomes, Human, Pair 14 (genetics)
• Female
• Genes, Recessive
• Genetic Variation
• Humans
• Male
• Middle Aged
• Muscular Dystrophy, Oculopharyngeal (genetics)
• Poly(A)-Binding Protein I (genetics)
• Sequence Analysis, DNA