engleski

Homozygozyty for facioscapulohumeral muscular dystrophy (FSHD) gene

To study phenotype-genotype correlation in one FSHD family in which the proband had two differently shortened EcoRI/Blnl fragments analyzed with probe p13E-11. FSHD is an autosomal dominant muscular disorder linked to a polymorphic D4Z4 locus on chromosome 4q35 but the gene has yet to be isolated. FSHD is associated with a short EcoRI/Blnl fragment (less than 35 kb ; fragment sizes between 35 and 48 kb must be interpreted with caution) resulting from deletion of an integral number of a 3.3 kb. Almost all the genes for FSHD, as other dominant disorders, are present in heterozygotes, who also possess a normal allele at this locus. For the gene to occur in the homozygous state requires one of several exceedingly rare events to occur. We present one such family. A 49-year-old proband from a four generation Croatian family in which at least thirteen individuals in three generations were affected, had moderate sensorineural hearing loss, a slowly progressive, late onset weakening of facial, shoulder and pelvic girdle muscles. His both parents might possess the FSHD gene because in both families hearing loss was noticed. Southern blot analysis using probe p13E-11 showed two shortened fragments of 34.5 kb and 38, 5 kb. Proband's 53-year-old brother, as well as his daughter and son, aged 25 and 21 years are affected and have smaller fragment of 38, 5 kb. It seems that homozygous form of FSHD has no increasing severity of clinical phenotype as compared with the heterozygote even with a larger EcoRI/Blnl fragment.

facioscapulohumeral muscular dystrophy; homozygosity; phenotype

6th WMS Congress: Poster Discussion Session 2 ; F.P.2.7