講演情報
[O24-5]BCOR遺伝子の新規変異を認めたOFCD症候群の1例
○山下 朋代1,2, 堀田 純子1,2, 浄弘 裕紀子1, 酒井 恵利1, 小野 智愛1, 馬場 遥香1, 鈴木 寿人3, 山田 茉未子3, 武内 俊樹4, 小崎 健次郎3, 依藤 亨5, 濱崎 考史2, 瀬戸 俊之1,2 (1.大阪公立大学大学院医学研究科 臨床遺伝学, 2.大阪公立大学大学院医学研究科 発達小児医学, 3.慶應義塾大学医学部 臨床遺伝学センター, 4.慶應義塾大学医学部 小児科, 5.伊達赤十字病院 第2内科)
Oculofaciocardiodental (OFCD) syndrome, also called microphthalmia syndrome 2, is characterized by ocular, facial, cardiac, and dental abnormalities. It is caused by a pathogenic variant in the BCL6 corepressor gene (BCOR), with X-linked dominant inheritance of male lethality. Our present case is a girl age 3 years 8 months. She has a high palate, interocular dissociation, narrow eye fissures, low-set auricles, bilateral radio-ulnar synostosis, flexion contracture of both hands, syndactyly of the bilateral second-third toes, bilateral cataracts, atrial septal defect, patent ductus arteriosus, and pulmonary hypertension. Her milestones were head control at 5 months, rolling over at 7 months, sitting at 1 year, independent walking at 2 years 6 months, and significant words at 2 years. G-banding showed 46,XX. A microarray chromosome test showed no abnormality. She was referred to our hospital at the age of 2 years 4 months for comprehensive genetic testing. Cornelia de Lange syndrome was suspected from the fused eyebrows and abnormal dentition. The genetic testing did not reveal pathogenic mutations. Whole exome trio analysis was performed by the Initiative on Rare and Undiagnosed Diseases. A heterozygous mutation c.2326del(p.His776Ilefs*10) in BCOR was identified only in the patient. From her symptoms and previous reports, we diagnosed OFCD syndrome. BCOR is a POZ/zinc finger transcriptional repressor that is required for germinal center formation and may affect apoptosis. To clarify the pathophysiology of BCOR, additional case reports on OFCD syndrome are needed.