Department of Pediatrics, University Hospital Félix Guyon, La Réunion, France.
Department of Medical Genetics, University Hospital Félix Guyon, La Réunion, France.
Eur J Med Genet. 2022 Oct;65(10):104598. doi: 10.1016/j.ejmg.2022.104598. Epub 2022 Aug 25.
The Bailey-Bloch congenital myopathy, also known as Native American myopathy (NAM), is an autosomal recessive congenital myopathy first reported in the Lumbee tribe people settled in North Carolina (USA), and characterized by congenital weakness and arthrogryposis, cleft palate, ptosis, short stature, kyphoscoliosis, talipes deformities, and susceptibility to malignant hyperthermia (MH) triggered by anesthesia. NAM is linked to STAC3 gene coding for a component of excitation-contraction coupling in skeletal muscles. A homozygous missense variant (c.851G > C; p.Trp284Ser) in STAC3 segregated with NAM in the Lumbee families. Non-Native American patients with STAC3 related congenital myopathy, and with other various variants of STAC3 have been reported. Here, we present seven patients from the Comoros Islands (located in the Mozambique Channel) diagnosed with STAC3 related congenital myopathy and having the recurrent variant identified in the Lumbee people. The series is the second largest series of patients having STAC3 related congenital myopathy with a shared ethnicity after le Lumbee series. Local history and geography may explain the overrepresentation of NAM in the Comorian Archipelago with a founder effect. Further researches would be necessary for the understanding of the onset of the NAM in Comorian population as search of the "classical" STAC3 variant in East African population, and haplotypes comparison between Comorian and Lumbee patients.
贝利-布洛赫先天性肌病，也称为美洲原住民肌病（NAM），是一种常染色体隐性先天性肌病，最初在北卡罗来纳州定居的卢比族人（美国）中报道，其特征为先天性无力和关节挛缩、腭裂、上睑下垂、身材矮小、脊柱侧凸和后凸、马蹄内翻足畸形以及对麻醉引发的恶性高热（MH）敏感。NAM 与 STAC3 基因相关，该基因编码骨骼肌兴奋-收缩偶联的一个组成部分。STAC3 中的纯合错义变异（c.851G>C；p.Trp284Ser）在 Lumbee 家族中与 NAM 分离。已报道了具有 STAC3 相关先天性肌病的非美洲原住民患者，以及具有其他各种 STAC3 变异的患者。在这里，我们介绍了来自科摩罗群岛（位于莫桑比克海峡）的七名患者，他们被诊断出患有 STAC3 相关先天性肌病，并携带在 Lumbee 人群中发现的反复变异。该系列是继 Lumbee 系列之后具有共享种族的第二大 STAC3 相关先天性肌病患者系列。当地的历史和地理可能解释了 NAM 在科摩罗群岛的代表性过高，存在创始效应。需要进一步研究才能了解科摩罗人群中 NAM 的发病机制，因为在东非人群中寻找“经典”STAC3 变异，并比较科摩罗和 Lumbee 患者的单倍型。
