A distinctive autosomal recessive syndrome of severe disproportionate short stature with short long bones, brachydactyly, and hypotrichosis in two consanguineous Arab families.

Disproportionate short stature is a heterogeneous group of hereditary disorders, which are classified according to their mode of inheritance, their clinical skeletal and non-skeletal manifestations, and their radiological characteristics. Herein, we inform on eight individuals with severe disproportionate short stature from two unrelated consanguineous families of Arab-Muslim ancestry. The adult height of the affected individuals is between 112 cm and 127 cm, and is due to pre- and post-natal growth retardation, which probably manifests as early as the second trimester of pregnancy. At a young age, the phenotype is characterized by a short stature, a relatively large head, and a long triangular face, and this phenotype later evolves to one with in which the head is relatively small, the mandible is large and pointy. The affected individuals have normal cognitive abilities and lack any neurological deficits. Other typical features include a prominent nose, a voice with an unusual high-pitched sound, relatively small ears, clinodactyly, brachydactyly, small hands, hypoplastic fingernails, a waddling gait, and sparse hair post-pubertally. Typical skeletal changes include short long bones, especially the femurs and humeri, with mild metaphyseal changes and very short femoral necks. After due consideration of the other hereditary causes of disproportionate short stature and close examination of the pedigrees of the two families, we concluded that these eight individuals have the same hitherto unreported form of severe disproportionate short stature that is inherited in the autosomal recessive mode.