4q and 10q allelic pattern of a FSHD family after hybridization with p13E-11 and qA-qB telomeric markers. a) DNA samples were digested with EcoRI (E) and EcoRI/BlnI (E/B) enzymes, separated with PFGE and hybridized with p13E-11 probe. The proband (I:1) shows a trisomic pattern with two 4q alleles of 18 and 30 kb and two 10q alleles of 41 (BlnI-resistant) (*) and 48 kb (BlnI-sensitive). The affected son (II:1) is also trisomic and inherited from the father the 4q FSHD allele of 18 kb and the10q of 41 kb (*) and from the mother the 4q of 53 kb and a similar size10q allele. The unaffected daughter inherited from the father the 4q allele of 30 kb and the 10q BlnI-resistant allele of 41 kb (*) and from the mother the 4q and 10q fragments of 53 kb. The segregation data for the probe D4S139 showed that II:1 and II:2 inherited the same 4q allele from the mother (I:2), but different 4q alleles from the father (I:1). This suggest that the BlnI-resistant allele of 41 kb is a 10q variant; b) DNA samples were digested with HindIII (H), separated with PFGE and subsequently hybridized with qA and qB probes: the short 4q allele (18 kb) is qA type, while the 4q allele of 30 kb is qB type. All the standard 10q alleles of 48, 53 and 20 kb have qA type telomeres, while the variant 10q allele of 41 kb is qB type. This variant 10q allele carries the Bln1-resistant repeat array and the distal telomeric sequence of 4q-type. The 10q origin of this allele is confirmed by absence of segregation with D4S139 probe. The DNA sample of the subject II:2 was not sufficient for qA/qB Southern Blot analysis and it was not included in figure 3. In the diagram below the alleles observed after EcoRI and EcoRI/BlnI digestion are shown: the 4q alleles are in bold and the telomeres (A or B) are in brackets.
Rossi et al. BMC Medical Genetics 2007 8:8 doi:10.1186/1471-2350-8-8