Abstract
One year and 10 months old boy with XYY syndrome was reported. He was born of a 32 year old mother who had had two normal children previously. Although no clinical abnormality was evident at birth, his development was delayed. He held his head at 6 months and sat alone at 1 year. Although he came to the age of 1 year and 10 months, he could neither walk alone nor speak anything.On physical examination, his weight was 12 kg (+0.4 SD) and his height 88cm (+1.4 SD). He had slightly apathetic facial appearance and brown hair. Neurological examination was normal except for slight muscle hypotonia. Routine laboratory studies were within normal limits. D.Q. scores was 47 by Tsumori and Inage scale for infant developmental test. Chromosome analysis revealed 47, XYY. Growth hormone showed late response after injection of insulin, TRH and LH-RH, but other pituitary hormones showed normal responses. CT scanning revealed low density area in the left temporal tip.
XYY syndrome is characterized by tall stature, aberrant behavior and mild mental subnormality. In 1961 Sandberg et al. reported the first case of XYY syndrome. Since Jacobs et al. reported a high frequency of 47, XYY individuals in penal institutions, an association between the extra Y chromosome and criminal or antisocial behavior was noticed. But in recent wider investigations XYY syndrome was found to be one of the most common chromosome abnormalities in man. And XYY men in normal development were reported. To establish clinical or behavioral characteristics of XYY syndrome, longitudinal prospective studies of XYY infants and children are necessary. It was interesting that this case revealed developmental delay and low density by CT scanning.
