Roberts syndrome
MIM.268300 8p21.1
Autosomal recessive disease. Severe midfacial and limb defects and birth length less than 37cm associated with stillborn or early infant death. Likely allelic with SC phocomelia syndrome (MIM.269000).
The rare, autosomal recessive Roberts syndrome (RBS) is characterized by tetraphocomelia, profound growth deficiency of prenatal onset, craniofacial anomalies, microcephaly, and mental deficiency.
Synopsis
low birth weight
birth length less than 40cm
birth weight 1.5-2.2 kg
severe prenatal growth deficiency
failure to thrive
mild-severe postnatal growth deficiency
craniofacial anomalies
- microcephaly
- brachycephaly
- microbrachycephaly
- micrognathia
- malformed ears
- lobeless ears
- low-set ears
- posteriorly-angulated ears
- hypertelorism
- shallow orbits
- prominent eyes or exophtalmy
- bluish sclerae
- corneal clouding
- microphthalmia
- cataract
- lid coloboma
- thin nares
- hypoplastic nasal alae
- widened nasal bridge
- cleft lip
- cleft palate
- short neck
- nuchal cystic hygroma
cardiovascular malformations
- atrial septal defect
- ventricular septal defect
- patent ductus arteriosus
rudimentary gallbladder
accessory spleen
genitoal anomalies
- hypospadias
- enlarged penis
- testicular agenesis (#11450388#)
- enlarged clitoris
- enlarged labia minora
- cryptorchidism
- bicornuate uterus
renal anomalies
- syndromal bilateral non-obstructive renal dysplasia (BNORD) (#11450388#)
- horseshoe kidney
skeletal and limb anomalies
- craniosynostosis
- hypomelia (more severe in upper limbs)
- phocomelia (tetraphocomelia) (Roberts-SC phocomelia)
- elbow contracture
- absence or reduction in length of humerus, radius, or ulna
- knee contracture
- absence or reduction in length of femur, tibia, or fibula
- wrist contracture
- syndactyly
- clinodactyly
- oligodactyly (ectrodactyly)
- ankle contracture
- talipes equinovalgus
- reduction in number of toes
midfacial capillary hemangioma
sparse hair
silvery blonde scalp hair
cerbral anomalies
- mental retardation
- frontal encephalocele
- hydrocephalus
- cranial nerve paralysis
polyhydramnios
Cytogenetics
premature separation of centromeric heterochromatin
normal karyotype
abnormal nuclear morphology
Etiology
Roberts syndrome is caused by mutation in
- ESCO2 gene (cohesion 1 homolog 2 gene) (MIM.609353) (The protein product of the ESCO2 gene is required for the establishment of sister chromatid cohesion during S phase)
- NIPPL gene
See also
SC phocomelia