Clinical Characteristics

In addition to the features listed on the Professionals general information page, the level of intellectual disability can be profound. Affected males have also manifested intrauterine and postnatal growth delays in the absence of growth hormone deficiency and the microcephaly can be progressive. Feeding difficulties have noted and can require a gastrostomy tube. Brain anomalies have comprised a thin or absent corpus callosum, cerebellar hypoplasia, Dandy-Walker malformation and abnormal formation of the gyri. The gait may be ataxic and hypotonia can be present. An aged appearance with a paucity of subcutaneous fat can be present, along with a high hairline with a broad or receding forehead, downslanting palpebral fissures, a broad nasal root, anomalous ears, wide mouth with widely spaced and peg-shaped teeth, and micro-retrognathia or a prominent chin. In addition to the sparse and brittle hair, eyebrows and eyelashes can also be thin or absent and dry skin that can be thickened has been observed. Other rare findings have included panhypopituitarism, cutis marmorata and congenital short esophagus. Chronic diarrhea has also been noted. Obligate female carriers have demonstrated 100% skewed X-inactivation and have also manifest short stature.