Postnatal growth and development in patients with sex chromosome aneuploidies excluding Turner syndrome – The Singapore experience

With increasing use of prenatal screening, sex chromosome aneuploidies (SCAs) are more frequently detected. Individuals with SCAs have variable physical and medical findings, and developmental and behavioural outcomes. This retrospective study describes the growth, development and clinical features of individuals with SCAs seen at the Genetics clinic in KK Women’s and Children’s Hospital, Singapore, between January 2011 and July 2014. Forty-seven patients were included in this study, comprising six groups: 47, XXY (Klinefelter syndrome); 47, XXY/46, XY; 47, XYY; 47, XYY/46, XY; 47, XXX; and other rare SCAs. The majority (39 patients, 82.9%) were detected prenatally. A developmental assessment was available for 44/47 (93.6%). Of these, 28 (63.6%) were delayed in at least one domain, though the delay was mild in the majority (17 patients) with improvement documented on follow-up. Among eight individuals diagnosed postnatally, global developmental delay was reported in 4 (50%), compared to none among those diagnosed prenatally. Growth appeared unaffected in most, with 11.9% (5 patients) having tall stature. While 63.6% of our patients had developmental delay in at least one domain, commonly affecting speech and language, the delay was mild in the majority. No prenatally diagnosed patient had global developmental delay. This information is valuable in genetic counselling, especially prenatally. (201 words).