Donetsk's regional specialized center of medical genetic and prenatal diagnosis, Ukraine.  

Synonyms: Russell-Silver syndrome, Silver-Russell dwarfism, Russell nanism, Russell syndrome.

Characteristics

Silver-Russell syndrome is a clinically heterogeneous condition characterized by severe intrauterine growth retardation with normal head circumference, poor postnatal growth, craniofacial features such as a triangular shaped face and a broad forehead, body asymmetry, and a variety of minor malformations. The phenotypic expression changes during childhood and adolescence. There can be a limb-length asymmetry resulting from the hemihypotrophy with decreased growth of the affected side. The facial features and asymmetry usually becomes more subtle with the age.

Variation in sexual development in association with hypospadias and cryptorchidism is present in about one third of the affected individuals. Urinary tract abnormalities include hydronephrosis, ureteral obstruction, pyelonephritis, urinary reflux, and kidney enlargement. Affected individuals may have feeding difficulties and fasting hypoglycemia.

Incidence

Uncommon, varies from 0.1-3 in 10,000 births, the male-to-female ratio is equal.

Genetics

This syndrome is a heterogenous condition. Most affected individuals represent the same phenotype rather than a specific disorder. The final diagnosis is mainly based on the clinical findings. 10% of affected individuals have maternal uniparental disomy for chromosome 7 (7q25)

Management

Usually, no alteration of the prenatal care is necessary.

Case report

A 21-year-old G2 P0 Caucasian woman, was referred to our unit for prenatal examination. Her previous pregnancy was terminated at 20 weeks of gestation due to hydrocephalus. The patient was of a very short stature, 146 cm, she had a clinodactyly of the 5th finger, a skin with Café-au-lait spots, a small triangular face, prominent  forehead, mandibular micrognathia with a pointed chin, wide mouth with down-turned corners. The mother of our patient had a very similar phenotype.

Our ultrasound examination at 18 weeks revealed fetus with an incipient symmetrical growth restriction, biometry corresponded to 17 weeks of gestation. There was a mild dilation of the lateral ventricles, 9 mm and ambiguous genitalia.  No other fetal anomalies were detected. A triple screen was negative.

Our follow-up examination two weeks later revealed a further growth restriction, ventriculomegaly, hypospadia and facial dysmorphism and clinodactyly of the 5th finger.

Our diagnosis based on the ultrasound findings was Silver-Russell syndrome. Patient decided to continue her pregnancy. Amniocentesis showed normal karyotype, 46 XY. Patient delivered at term, the newborns's weight was 2200 grams. A geneticist confirmed our prenatal diagnosis of Silver-Russell syndrome.

Images 1,2: Image 1 shows a fetal profile. Image 2 shows a lateral ventricle measuring 9 mm.