Young-Simpson syndrome (YSS), a variant of del(1)(p36) syndrome?

The Young-Simpson syndrome (YSS) and 1p36 deletion syndrome are both characterized by facial and heart abnormalities, congenital hypothyroidism, and severe growth and developmental retardation. However, the YSS is characterized by the presence of blepharophimosis and epicanthus inversus, findings not described in monosomy 1p36 patients. We describe a girl with YSS, who presented with the typical facial findings, global retardation, congenital hypothyroidism, and congenital dilated cardiomyopathy. Comparative genomic hybridization chromosomal microarray analysis showed a 1p36.3 deletion, a finding not previously reported in other YSS cases. We propose that YSS is a variant of the 1p36 deletion syndrome.