Silver-Russell syndrome (SRS) is a very rare genetic disorder characterized by intrauterine growth retardation, difficulty in feeding, failure to thrive, poor growth, short stature, and asymmetry in size of the two halves or parts of the body. Disease onset is usually in early childhood and the patients appear to have triangular face with broad forehead, small pointed chin, and thin wide mouth. Shortness and/or clinodactyly of the fifth fingers are common findings. Patients may be slow to learn motor skills. To achieve optimal nutrition, a feeding tube may be helpful. Also, growth hormone therapy can enhance the growth process. Incidence ranges from 1 in 3,000 to 1 in 100,000 worldwide and more than 500 cases have been reported with equal male-to-female ratio.
Silver-Russell Syndrome occurs mostly due to epigenetic changes at the ICR1 region on chromosome 11. A genetic defect in chromosome 7 (maternal uniparental disomy of chromosome 7) has also been identified in about 10% of the patients.
Fuleihan et al. (1971) presented the first occurrence of Silver- Russell Syndrome (SRS) in Lebanon in three siblings born to consanguineous parents of Kurdish origin. One of the siblings was an 11-month-old boy, the other was 8-year-old girl, and the third was 8-day-old boy. The physical growth of the eldest brother was retarded since birth; however, his developmental milestones were normal. The sister had abnormal physical development with normal developmental milestones. All the siblings showed similar skull and facial features. They had pronounced craniofacial disproportion, enlarged cranium, triangular face, "inverted V-shaped" mouth, short stature, no significant asymmetry, and high arched palate. Café-au-lait spot appeared on the left thigh of the eldest boy and on the abdomen of the girl, whereas no such spot was evident in the youngest boy. The chromosomal karyotyping displayed normal 46,XY pattern for the eldest boy, and normal 46,XX pattern for the girl. The bone age corresponded to a chronologic age of nine to 12 months in the eldest brother, six to 6 and half years in the sister, and 36 to 38 weeks of intrauterine gestation in the youngest brother. There was a history of short stature on both sides of the family. Although the mother had short stature, it could not be decided whether she had features of SRS in the childhood because they would have changed and gradually disappeared in adulthood. Fuleihan et al. (1971) supported the theory of representing fresh mutations as the etiology of SRS, and so an autosomal dominant form of inheritance would seem to be the most possible.
Chammas et al. (1997) reported the case of a Lebanese girl of 11 months of age with Russel-Silver syndrome. She was the second child on non-related Lebanese parents. Upon examination she presented a large and bossed front with relative mandibular hypoplasia with an "inverted triangle" facial appearance. The upper and lower lips were very thin and with falling borders. She also had some spots of café-au-lait on her body and left cheek. Bilateral clinodactyly occurred at the 5th digit as well as syndactyly of the second and third digits of the left foot were present. Chromosome analysis revealed a normal karyotype. Intelligence and psychomotor development were also normal. [Chammas C, Haddad J, Souraty N, Megarbane A. Le syndrome de Russel-Silver: description d'un cas et revue de la litterature. Rev Med Libanaise 1997; 9:152-4.]