Williams syndrome (syndrome of idiopathic hypercalcemia)

Williams syndrome was first described in 1961 by J.C.P. Williams et al. The population frequency is 1:7500-10 000 live births; the ratio of boys and girls is about 1:1. The nature of this genetic disease is the loss of genetic material (microdeletion) of the long arm of chromosome 7. During microdeletion the loss of elastin, LIM-kinase-1 and replication factor C2 (RFC) genes occurs, some of the «lost» genes have not yet been identified. A more rare form of the syndrome exhibits deletions on chromosomes 11 and 12 - 11q13-q14, and 22q. Presented was the authors’ clinical observation. A child was born from the second pregnancy (the first one ended in miscarriage at 12 weeks of the term), which had a physiological course, first childbirth was given at the term of 40 weeks, the newborns body weight at birth was 2600 g, body length 49 cm. At 1 year 8 months the baby’s height was 80 cm, body weight was 10 kg 800 g, head circumference - 50 cm, chest circumference - 51 cm. Multiple stigmas of dysembryogenesis were present. The head was irregularly shaped, the large fontanelle was closed. A marked face dysmorphism: a broad forehead, the unusual shape of the eyes with swelling around them, epicanthal fold, drooping full cheeks, the characteristic shape of the nose with a rounded blunt end and anteriorly open nostrils, a small pointed chin, a large open mouth, full lips, especially the lower one, progeny, small teeth, jagged, and affected by caries. The thorax was narrow, a depressed sternum in the form of a «сobbler’s chest». The muscle tone was moderately reduced. The psychomotor development at the level of a 8-9 months old. Cardiologist’s conclusion: a congenital heart defect, hypoplasia of the isthmus of the aortic arch. Conclusion of the geneticist: multiple stigmas of dysembryogenesis, a characteristic phenotype. Karyological analysis 46,XY - without karyotype abnormalities. Chromatography of the amino acids - without any pathology. Diagnosis: Williams syndrome. Diagnosis of Williams syndrome sometimes possesses known difficulties. The described clinical case illustrates the possibilities of diagnosing the syndrome, based primarily on a careful analysis of the medical history, of the clinical picture and physical examination.