Roberts Syndrome (Including SC Phocomelia)
Autosomal recessive
Caused by loss-of-function changes in both copies of ESCO2, which encodes an enzyme needed for sister chromatid cohesion during cell division. A characteristic finding on chromosome testing is premature separation of the centromeres.
Signs and symptoms
Growth restriction before and after birth with shortening of the arms and legs, usually affecting the arms more than the legs and ranging from absent limb segments to milder differences. Cleft lip and palate and distinctive facial features are typical, and a small head may occur. Intellectual disability occurs in about half of people; the milder end of the spectrum was previously called SC phocomelia.
What a diagnosis changes
Care involves orthopaedic and limb support, cleft and craniofacial surgery, and developmental assessment. Both parents of an affected child are usually carriers, so each further child has a 1 in 4 chance of being affected; genetic counselling and carrier testing of relatives are available.
Genes analysed
Also known as
Appelt-Gerken-Lenz syndrome; ESCO2 spectrum disorder; hypomelia hypotrichosis facial hemangioma syndrome; long bone deficiencies associated with cleft lip-palate; phocomelia-pseudothalidomide syndrome; pseudothalidomide syndrome; RBS; Roberts syndrome; Roberts syndrome/SC phocomelia; Roberts tetraphocomelia syndrome; SC phocomelia; SC phocomelia syndrome; SC phocomelia syndrome (mild variant of Roberts syndrome); SC pseudothalidomide syndrome; tetraphocomelia-cleft palate syndrome
