221Walker-Warburg Syndrome (WWS) (Walker-Warburg綜合症)
222WDR45 (Genetic Disorder)
223Wells Syndrome (韋爾斯綜合症)
224West Syndrome-Infantile Spasms (韋氏症-嬰兒痙攣症)
225Williams Syndrome (WS) (威廉氏症候群)
226Wilson's Disease (WD) (威爾森氏症)
227Wolf-Hirschhorn Syndrome (WHS) (沃夫-賀許宏氏症候群)
228Wolfram Syndrome (Wolfram症候群)
229Worster-Drought Syndrome (WDS)
230WWOX Syndrome (Genetic Disorder)
231Xeroderma Pigmentosum (XP) (著色性乾皮症)
232X-linked Agammaglobulinemia (XLA) (X-連鎖無丙種球蛋白血症)
233X-linked Hypophosphatemic Rickets (XLH) (性聯遺傳型低磷酸鹽佝僂症)
234X-linked Myotubular Myopathy (XLMTM) (肌小管病變)
235X-linked Retinoschisis (XLRS) (Genetic Disorder)
236X-linked Thrombocytopenia (XLT) (Genetic Disorder)