Inheritance patterns of ATCCT repeat interruptions in spinocerebellar ataxia type 10 (SCA10) expansions
Fig 1
The ATCCT repeat interruption is stable through generations.
(A) Schematic of an average length SCA10 expansion allele demonstrating the relative location of the priming sites for the ATCCT PCR amplification and sequencing primers and the relative size of the ATCCT product. White box, ATTCT repeats; hatched black and white box, interruption motifs; green box, presumed pure tract of tandem ATCCT repeat motifs; black box, flanking non-expansion sequences. (B) Detailed schematic of repeat motifs within the ATCCT product. Allele 5 is depicted. White rectangles, ATTCT repeat; orange, ATTTTCT; blue, ATATTCT; green, ATCCT. (C) Seven interruption alleles were observed based on the number of ATTCT repeats observed within each polymorphic stretch (alpha, beta, gamma, delta, epsilon, zeta and eta). (D) SCA10 family pedigrees, only SCA10-positive individuals are shown. Generations are indicated by roman numerals to the left of each pedigree. Square (males) and circles (females) are color-coded by repeat interruption group. Black, undetermined allele; light blue, allele 1; green, allele 2; red, allele 3; yellow, allele 4; grey, allele 5; dark blue, allele 6; tan, allele 7. Numbers below male/female symbols indicate the SCA10 expansion size (in repeat units) determined via Southern blotting; n.d. indicates that the SCA10 expansion size was not determined due to insufficient DNA quality. Thick blue lines, paternal transmissions examined; thick red lines, maternal transmissions examined.