Sex Chromosome Aneuploidies: DSD Perspective

Sex chromosome aneuploidies are a group of chromosomal disorders that are characterised by loss or gain of one or more sex chromosomes. These disorders are usually underdiagnosed despite them being more prevalent in the general population. Turner syndrome, Klinefelter syndrome, Trisomy X, Trisomy XYY and Tetrasomy XXYY are the five major sex chromosomal aneuploidies. Of these, Klinefelter syndrome is the most common with an incidence of 1 in 600–750 live births. It is typically characterised by tall stature, gynaecomastia, small firm testes, hypergonadotrophic hypogonadism and azoospermia but the presentation may vary according to the age of presentation. Multidisciplinary team approach is required for optimal care and better outcomes.