Abstract：
Dystroglycanopathies are a group of congenital muscular dystrophies (CMDs) that include a broad phenotypic spectrum ranging from late-onset limb-girdle muscular dystrophy to severe muscle-eye-brain disease, Walker-Warburg syndrome, and Fukuyama congenital muscular dystrophy. In addition to clinical heterogeneity, CMDs are characterized by genetic heterogeneity. To date, 18 genes have been associated with CMDs. One of them is B3GALNT2, which encodes the β-1,3-N-acetylgalactosaminyltransferase 2 that glycosylates α-dystroglycan. In this study, using exome sequencing, we identify a homozygous frameshift variant in B3GALNT2 due to a mixed uniparental disomy of chromosome 1 in a 7-year-old girl with global developmental delay, severely delayed active language development, and autism spectrum disorder but without any symptoms of muscular dystrophy. In addition to this case, we also provide an overview of all previously reported cases, further expanding the phenotypic spectrum.
摘要：
营养不良症是一组先天性肌营养不良症（CMD），包括广泛的表型范围，从晚发性肢带肌营养不良到严重的肌眼脑疾病，Walker-Warburg综合征,和福山先天性肌营养不良症。除了临床异质性，CMD的特征在于遗传异质性。迄今为止,已有18个基因与CMD相关。其中之一是B3GALNT2，它编码β-1,3-N-乙酰半乳糖胺转移酶2，该酶可糖基化α-营养不良聚糖。在这项研究中,使用外显子组测序，我们发现了B3GALNT2中的一个纯合移码变异体，这是由于一个7岁女孩的1号染色体混合单亲二体性导致的，严重延迟主动语言发展，和自闭症谱系障碍，但没有任何肌肉萎缩症的症状。除了这个案例,我们还提供了以前报告的所有病例的概述，进一步扩大表型谱。
