A family with three affected males and a second family with a single affected male with intellectual disability, microcephaly, ophthalmoplegia, deafness, and Involuntary limb movements were reported by Schimke and Associates in 1984. The affected males with Schimke X‐linked intellectual disability (XLID) syndrome (OMIM# 312840) had a similar facial appearance with deep‐set eyes, downslanting palpebral fissures, hypotelorism, narrow nose and alae nasi, cupped ears and spacing of the teeth. Two mothers had mild hearing loss but no other manifestations of the disorder. The authors considered the disorder to be distinctive and likely X‐linked. Whole genome sequencing in the single affected male available and the three carrier females from one of the families with Schimke XLID syndrome identified a 2 bp deletion in the BCAP31 gene. During the past decade, pathogenic alterations of the BCAP31 gene have been associated with deafness, dystonia, and central hypomyelination, an XLID condition given the eponym DDCH syndrome. A comparison of clinical findings in Schimke XLID syndrome and DDCH syndrome shows them to be the same clinical entity. The BCAP31 protein functions in endoplasmic reticulum‐associated degradation to promote ubiquitination and destruction of misfolded proteins.

中文翻译：

---

Schimke XLID综合征是BCAP31缺失导致的。

1984年，Schimke and Associates报道了一个有三名受影响男性的家庭和第二个有一位患有智力残疾，小头畸形，眼肌麻痹，耳聋和肢体不自主运动的受影响男性的家庭。受影响的男性患有Schimke X连锁智力障碍（XLID）综合征（OMIM＃312840）具有类似的面部外观，眼睛深陷，睑裂向下倾斜，视力减退，鼻子和鼻翼狭窄，耳朵凹陷和牙齿间隔。两名母亲患有轻度听力下降，但没有其他表现。作者认为这种疾病是独特的，并且可能与X相关。在单一的男性患者可与三个载波女性全基因组测序从Schimke XLID综合征的家族之一确定了2 bp缺失在BCAP31基因。在过去的十年中，BCAP31基因的致病性改变与耳聋，肌张力障碍和中枢性髓鞘减少有关，这是同名DDCH综合征的XLID病状。Schimke XLID综合征和DDCH综合征的临床发现比较表明，它们是同一临床实体。BCAP31蛋白在内质网相关降解中起作用，以促进错折叠蛋白的泛素化和破坏。