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.

Two rare cases of 6p partial deletion (6p23-rpter) are described. Both patients are at or past the adolescent stage, with severe mental retardation and severe to moderate developmental retardation. Physical dysmorphic features that stand out are: short forehead, borderline microcephaly, low-set malformed ears, hyperplastic nares, dental anomalies and short terminal phalanges. The diversity of the phenotypic features has considerable variations in patients with ring of 6, apparently reflecting the relative loss of p and q arms. A case of a larger terminal deletion and a report of an interstitial deletion is also reviewed.