121Kleefstra Syndrome (KS) (Kleefstra綜合症)
122Klippel-Trénaunay Syndrome (KTS) (静脈畸形骨肥大綜合症)
123Langerhans Cell Histiocytosis (LCH) (蘭格罕細胞組織球增生症)
124Larsen Syndrome (颚裂-先天性脱位症候群)
125Leber's Congenital Amaurosis - Type 1 (LCA1) (Genetic Disorder) (先天性黑蒙症 - 第一型) (基因突變)
126Leber's Congenital Amaurosis - Type 3 (LCA3) (Genetic Disorder) (先天性黑蒙症 - 第三型) (基因突變)
127Leigh Syndrome (Leigh氏症候群)
128Leiomyosarcoma (LMS) (平滑肌肉瘤)
129Leopard Syndrome (豹皮症候群)
130Limb-girdle Muscular Dystrophy (LGMD) - Type 2A (肢帶型肌肉失養症 - 第2A型)
131Linear Scleroderma (線性硬皮症)
132Lissencephaly (平腦症)
133Lymphangioleiomyomatosis (LAM) (淋巴管平滑肌增生症)
134Maple Syrup Urine Disease (MSUD) (楓糖尿症)
135Marfan Syndrome (MFS) (馬凡氏症)
136McCune-Albright Syndrome (MAS) (纖維性骨失養症)
137Medulloblastoma (髓母細胞瘤)
138Melanomae / Eye Ciliary Body Tumor (眼睫狀體黑色素瘤)
139Mesothelioma (間皮瘤)
140Methylmalonic Acidemia (MMA) (甲基丙二酸血症)