OMIM ID:
Roberts Syndrome
Alternate Names
Defective Genes
Clinical Characteristics
Ocular Features
The eyes often appear prominent as the result of shallow orbits. Hypertelorism and microphthalmia can be present. The sclerae can have a bluish hue. Cataracts and central corneal clouding plus scleralization and vascularization of the peripheral corneas are sometimes seen. Lid colobomas and down-slanting palpebral fissures may be present.
Systemic Features
Failure of both membranous and long bones to grow properly lead to a variety of abnormalities such as craniosynostosis, hypomelia, syndactyly, oligodactyly, malar hypoplasia, short neck, micrognathia, and cleft lip and palate. The long bones of the limbs may be underdeveloped or even absent. Contractures of elbow, knee, and ankle joints are common as are digital anomalies. Low birth weight and slow postnatal growth rates are usually result in short stature. The hair is often sparse and light-colored.
Mental development is impaired and some children are diagnosed to have mental retardation. Cardiac defects are common. Facial hemangiomas are often present as are septal defects and sometimes a patent ductus arteriosus. External genitalia in both sexes appear enlarged. The kidneys may be polycystic or horseshoe-shaped.
Genetics
Inheritance
This is an autosomal recessive condition caused by mutations in the ESCO2 gene (8p21.1). Mutations in the same gene are also responsible for what some have called the SC phocomelia syndrome (269000) which has a similar but less severe phenotype. Some consider the two disorders to be variants of the same condition and they are considered to be the same entity in this database. The gene product is required for structural maintenance of centromeric cohesion during the cell cycle. Microscopic anomalies of the centromeric region (puffing of the heterochromatic regions) are sometimes seen during cell division.
The Baller-Gerold syndrome (218600) has some phenotypic overlap with Roberts syndrome but is caused by mutations in a different gene (RECQL4).
Pedigree
Autosomal recessive
In order for autosomal recessive disorders to be expressed, offspring generally must inherit two mutations, one from each carrier parent. Carriers with only one mutation, such as the parents, do not have clinical disease. Note that carrier parents can expect that 1 in 4 children (25%) will inherit both mutations and have the disorder, 2 in 4 children (50%) will be carriers like their parents, while 1 in 4 children (25%) inherit neither mutation.
In order for autosomal recessive disorders to be expressed, offspring generally must inherit two mutations, one from each carrier parent. Carriers with only one mutation, such as the parents, do not have clinical disease. Note that carrier parents can expect that 1 in 4 children (25%) will inherit both mutations and have the disorder, 2 in 4 children (50%) will be carriers like their parents, while 1 in 4 children (25%) inherit neither mutation.