RING CHROMOSOME 5 IN A CHILD WITH SEVERE GROWTH RETARDATION

Abstract

We report the fourth case known of ring chromosome 5 with phenotype resembling that of the “ring syndrome”. A female child of healthy, unrelated, Italian parents, was referred for diagnosis at 36 months of age because of growth retardation, microcephaly and clinodactyly. Her parents' and sister's height fell within normal range. The girl was born after a normal pregnancy. Delivery was posterm, at 42 weeks, spontaneous. At birth weight was 2,480 Kg (−2SD), length 47 cm (−2.5SD), head circumference 32 cm (−1.8SD), no further abnormalities were noted. The first milestones were reached in time. On admission, her length was 85 cm (−3.2SD), weight 10,900 kg (−2SD), head circumference 46 cm (−2SD). Mild psycological abnormalities and a discrepancy between verbal and nonverbal areas were noted. The mean growth hormone secretion (sampling every 30 min over 24 hours) was 2.3 ± 0.4 ng/ml. The stimulated secretion showed a partial deficiency: peak after arginine (0.5 gr/kg, iv, over 30 min) 8.4 ng/ml; peak after clonidine (150 mg/m2 orally) 6.8 ng/ml, Bone age was delayed by 1 year. Chromosome analysis showed a ring chromosome 5 in 88%of the cells, a double ring in 2% and two rings in 1%, while in 9% the ring was lost. No delections were found. The sister's and parent's chromosomes were normal. This is the first case of ring chromosome 5 associated with a stimulated partial GH deficiency.