Elastin region deletions in Williams syndrome

Clinical manifestations and molecular investigation of 50 patients with Williams syndrome in the Greek population

Williams syndrome (WS) is a well-recognized neurodevelopmental disorder manifested by both connective tissue and CNS abnormalities. The study depicts the 8-y experience and follow-up of 50 Greek children with the clinical diagnosis of WS. Clinical data on the facial features and cardiovascular, endocrinologic, and neurodevelopmental evaluation are presented. The most consistent findings were dysmorphic features (100%), followed by dental anomalies (90%) and hyperacousis (90%). Only eight of 50 children had severe cardiovascular defects that required surgical intervention during the first year of life. Supravalvular aortic stenosis was less frequent (28%) than shown in the literature. Severe hypertension was noticed in 22% of our patients, and infantile hypercalcemia was noticed in 6%. Twelve percent of our patients showed an elevation of CPK. Most children presented with moderate to severe mental retardation with IQ ranging from 20 to 85. Elastin hemizygosity was detected by fluorescence in situ hybridization. Dinucleotide repeat polymorphism analysis was performed in an attempt to correlate phenotype with genotype. The origin of deletions was more frequently maternal (59%), and a more severe phenotype seemed to be associated with those deletions. This is the first report on WS patients in the Greek population.

Perinatal calcium metabolism: physiology and pathophysiology

Disturbances in mineral homeostasis are common in the neonatal period, especially in premature infants and infants who are hospitalised in an intensive care unit. In many cases these disturbances are thought to be exaggerated responses to the normal physiological transition from the intrauterine environment to neonatal independence. By contrast, some disturbances in calcium homeostasis are the result of genetic defects, which in many instances can now be identified at the molecular level. In other cases hypocalcaemia or hypercalcaemia may result from pathological intrauterine conditions, birth trauma or stress, or fetal immaturity. Diagnosis and management of hypocalcaemia and hypercalcaemia in the neonate and infant requires specific knowledge of perinatal mineral physiology and the unique clinical and biochemical features of newborn mineral metabolism. In this chapter we will provide a brief overview of calcium metabolism with an emphasis on the neonatal transition, followed by discussion of the common causes of hypercalcaemia and hypocalcaemia.