Mackinder's hereditary brachydactyly: phenotypic, radiological, dermatoglyphic and genetic observations in an Ontario family

Brachydactyly Type B: Clinical Description, Genetic Mapping to Chromosome 9q, and Evidence for a Shared Ancestral Mutation

“…Both families described herein had features of BDB that were similar to those elsewhere reported in other families of English ancestry (MacKinder 1857;Clarke 1915;Cragg and Drinkwater 1917;MacArthur and McCullough 1932;Wells andPlatt 1934: Malloch 1957;Battle et al 1973). Common to all families are fingernail aplasia or hypoplasia involving digits 2-5; reduction deformity of the hands and the feet, with radiographically demonstrated hypoplasia or absence of distal and middle phalanges; normal-appearing great toes; and absence of major extra-apical manifestations.…”

“…1). Four BDB kindreds-three English and one Canadian-had ancestors from Lincolnshire, Nottingham, or Manchester, in the northwest region of England (Clarke 1915;Cragg and Drinkwater 1917;Wells and Platt 1934;Malloch 1957;Battle et al 1973), leading to speculation that the families may share a common ancestor (MacArthur and McCullough 1932;Battle et al 1973). Supporting this is our confirmation (authors' unpublished data) that this disease-associated haplotype (from D9S1836 to D9S197) is shared by two additional BDB families, which were investigated independently by Oldridge et al (1999).…”

“…Consequently, one could speculate that, were disruption of limb development the likely cause of BDB, then the timing of the disruption would likely occur around the 7th or 8th gestational week. Further support for a disruptive mechanism in the causation of BDB is the appearance of scarring at the fingertips in several patients (Battle et al 1973) and the lack of normal dermatoglyphic patterns (MacArthur and McCullough 1932;Battle et al 1973). The red bleb occurring on one of the fingers of individual IV-1 of family 2, which subsequently went black and fell off, has been described in both the murine and the rabbit disorders.…”