growth deficiency

Roberts Syndrome

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

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
Treatment
Treatment Options: 

Severely affected infants may be stillborn or die in infancy.  Other individuals live to adulthood.  There is no treatment for this condition beyond specific correction of individual anomalies.

References
Article Title: 

Retinitis Pigmentosa and Mental Retardation

Clinical Characteristics
Ocular Features: 

The lenses may have pleomorphic white axial opacities but in other patients can be totally opacified.  Optic atrophy is present and vision may be reduced to light perception but nystagmus is absent.  Evidence suggests that vision loss is progressive.  Some patients have extensive posterior synechiae while others have been noted to have sluggish pupils.  High myopia is a feature. The retinal pigmentation has a typical retinitis pigmentosa picture with attenuated retinal vessels and equatorial bone spicule pigmentation located in the midperiphery while the macula can have a bull’s eye appearance.   

Systemic Features: 

Early development may seem normal but developmental milestones are usually delayed.  Postnatal microcephaly and growth deficiency with mental retardation and early hypotonia are typical features.  The mental retardation may be severe.  Scoliosis and arachnodactyly have been noted and hypogonadism has been reported.  Speech may not develop and mobility is sometimes limited.

Genetics

The family pattern suggests autosomal recessive inheritance.  Homozygosity mapping has identified in a region of chromosome 8 (8q21.2-22.1) that overlaps the region for Cohen syndrome () but no specific mutated gene has been identified.      

Pedigree: 
Autosomal recessive
Treatment
Treatment Options: 

None.

References
Article Title: 
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