Roberts syndrome

Roberts syndrome (also known as Roberts-SC phocomelia syndrome or pseudothalidomide syndrome) is a rare autosomal recessive genetic disorder characterized by symmetric limb reduction defects, craniofacial abnormalities, and prenatal and postnatal growth retardation. The condition is caused by mutations in the ESCO2 gene, which encodes a protein essential for proper sister chromatid cohesion during cell division. A characteristic cytogenetic finding is premature centromere separation (also called heterochromatin repulsion or puffing), which can be observed on chromosome analysis and aids in diagnosis. The limb abnormalities range from mild shortening (hypomelia) to severe reduction or near-complete absence of limbs (phocomelia), and typically affect the upper limbs more severely than the lower limbs. Craniofacial features may include bilateral cleft lip and/or cleft palate, hypertelorism (widely spaced eyes), exophthalmos (protruding eyes), a small head (microcephaly), hypoplastic nasal alae, and ear anomalies. Additional features can include congenital heart defects, renal anomalies, intellectual disability, and thrombocytopenia. The clinical severity is highly variable, with the most severely affected individuals often dying in the prenatal or neonatal period, while milder cases (sometimes referred to as SC phocomelia syndrome) may survive into childhood or adulthood. There is no cure for Roberts syndrome, and management is supportive and symptomatic. Treatment may involve surgical correction of cleft lip and palate, orthopedic interventions for limb abnormalities, cardiac surgery if heart defects are present, and developmental support services. Prenatal diagnosis is possible through ultrasound detection of limb anomalies and cytogenetic analysis of fetal cells. Genetic counseling is recommended for affected families.

Common questions about Roberts syndrome