A rare type of ectodermal dysplasia. Less than 50 cases have been described in the literature so far. Clinically, the syndrome has characteristics of severe hand and/or foot anomalies, and hypoplasia/aplasia of the mammary gland and nipple. Clinical expression is extremely variable. Individuals with mild LMS have isolated athelia. All three major categories of limb defects (i.e., deficiencies, duplications and fusion/separation defects), as well as several combinations of these anomalies, were observed. Variation in the severity of the limb defects may be observed, not only between individuals but also between the left and right hand/foot of one individual. Skin and hair are spared. An autosomal dominant disease caused by loss-of-function mutations in exon 13 and 14 of the TP63 gene found on the subtelomeric region of chromosome 3 (3q27).