Clasped‐thumb mental retardation (MASA) syndrome: Confirmation of linkage to Xq28

Abstract

We describe a 5-generation Hispanic family with 13 males and 1 female affected with MASA syndrome. The proposita, a 17-year-old female, and her affected male relatives shared many of the cognate manifestations--mental retardation (14/14), aphasia or delayed speech (13/13), shuffling gait (8/13), adduction of thumbs (14/14)--as well as scoliosis (2/13) and increased deep tendon reflexes in the lower extremities (10/13). Southern analysis with the polymorphic DNA probes DXS14 (Xp11), DXS72 (Xq21), and F8C (Xq28) confirmed linkage to the Xq28 region with a maximum lod score of 3.01 for this family.

Role of the cytoplasmic domain of the L1 cell adhesion molecule in brain development

“…Adducted thumbs are typically present at birth and might be due to failure of innervation of the adductors in the forearm (Holtzman et al, 1976; Kanemura et al, 2006). Macias et al found the human mutation (S1181X) that causes the truncation of L1 protein, similar to our L1 1180 mice (Macias et al, 1992; Weller and Gartner, 2001). This human mutation did not cause hydrocephalus or corpus callosum hypoplasia, but it did cause spastic paraplegia and adducted thumbs.…”

Congenital hydrocephalus: Nosology and guidelines for clinical approach and genetic counselling

“…Carrier detection can be performed by DNA linkage analysis with distal Xq28 markers, if the family is large enough and if there is (are) male patient(s) alive. In females minor features of the spectrum can be found such as adducted thumbs and subnormal intelligence or even the full-blown clinical picture of MASA syndrome [7,25,28,36,45]. If DNA linkage analysis is not possible, an a priori recurrence risk can be calculated from the pedigree.…”

Index finger hyperphalangy and multiple anomalies: Catel‐manzke syndrome?

“…MATERIALS AND METHODS Transformed lymphocyte cultures were prepared from the relatives indicated in Figure 2 and DNA was extracted as described (Macias et al, 1992). DNA linkage studies employed the probes DXS72 (Xq2l-Hind I11 polymorphism) and F8C (Xq28-BcZ I polymorphism).…”

“…DNA linkage studies employed the probes DXS72 (Xq2l-Hind I11 polymorphism) and F8C (Xq28-BcZ I polymorphism). Southern analysis and probe labeling were as described (Macias et al, 1992).…”