We report a case of UPD6mat discovered through CAH. The one previous case of UPD6mat (Van den Berg-Loonen, et al., Hum Immunol 1996; 45;46) was discovered during HLA analysis for renal transplantation in a 40 year old man with adult onset renal disease who had been healthy except for intrauterine growth retardation (IUGR).
Our patient presented at 2.65 years of age with a history of possible clitoral enlargement since birth and pubarche for 3 months. The patient was born with IUGR; birth size was 1410 gm, 39.5 cm at 37 weeks gestation. Her growth had caught up to the 5th percentile at 18 months of age. At 2.65 yr, her height was 85th percentile and weight 25th percentile. She had a history of early developmental delay, frequent minor respiratory illnesses and low IgA levels. IQ was 127. Work-up revealed elevations of plasma 17-hydroxyprogesterone (2054 ng/dl; normal <150) and testosterone 54 ng/dl(<20). Bone age was 3.67 years. The diagnosis of simple virilizing CAH was confirmed by DNA mutation analysis. The patient was homozygous for the 1172N Exon 4 mutation, by allele specific PCR and Southern blotting. When parental DNA was examined, the mother was found to carry one copy of the Exon 4 mutation, while the father had no detectable mutations. Because 1172N accounts for only 8.4% of mutations in CAH (Wilson et al., JCEM 1995; 80:2232), we suspected UPD6mat.
