We report on a man with short stature, bilateral early-onset cataracts, HH and an inherited 44.8 kb deletion of chromosome Xq28 encompassing the entirety of FUNDC2, exons 2–3 of CMC4, and exons 2–5 of MTCP1. Clinical evaluation excluded other known genetic and acquired causes of HH, including Klinefelter syndrome, testicular torsion, previous infection, or exposure to radiation or medications. The gene discussed is MTCP1; the disease is Klinefelter syndrome.