Hamel et al. (1999) described a 6-generation family segregating X-linked mental retardation. Affected members demonstrated nonprogressive mental retardation during childhood and had large, simple ears, relatively large hands, and normal behavior. The propositus also had clinodactyly of the ... Hamel et al. (1999) described a 6-generation family segregating X-linked mental retardation. Affected members demonstrated nonprogressive mental retardation during childhood and had large, simple ears, relatively large hands, and normal behavior. The propositus also had clinodactyly of the fifth fingers and flat feet; findings in other affected individuals included short stature, high-arched palate, high nasal bridge, full lips, and large testes. The mental retardation in family MRX45 ranged from mild to severe: most affected members showed higher adaptive than intellectual functioning, and most could read, write, and solve simple arithmetic problems.
In a female patient with severe mental retardation and a de novo translocation t(X;9)(p11.23;q34.3), Kleefstra et al. (2004) characterized the breakpoints and found that the translocation disrupted the ZNF81 gene. Mutation analysis in more than 300 families and ... In a female patient with severe mental retardation and a de novo translocation t(X;9)(p11.23;q34.3), Kleefstra et al. (2004) characterized the breakpoints and found that the translocation disrupted the ZNF81 gene. Mutation analysis in more than 300 families and patients with nonspecific X-linked mental retardation revealed a ser179-to-asn mutation (314998.0001) in ZNF81 in the MRX45 family reported by Hamel et al. (1999).