Spinobulbar muscular atrophy (SBMA) is an X-linked adult-onset neuromuscular disorder that causes progressive weakness and androgen insensitivity in hemizygous males. This condition is reported to be extremely rare, but has higher prevalence in certain populations due to multiple founder effects. Anecdotal observations of a higher prevalence of SBMA in patients of Indigenous descent in Saskatchewan led us to perform this study, to estimate the disease prevalence, and to attempt to identify a founder effect.

For our prevalence estimation, we identified patients with confirmed SBMA diagnosis from the Saskatoon neuromuscular clinic database for comparison with population data available from Statistics Canada. For our haplotype analysis, participants with SBMA were recruited from 2 neuromuscular clinics, as well as 5 control participants. Clinical data were collected, as well as a DNA sample using saliva kits. We performed targeted quantification of DXS1194, DXS1111, DXS135, and DXS1125 microsatellite repeats and the AR GGC repeat to attempt to identify a disease haplotype and compare it with prior studies.

We estimate the prevalence of SBMA among persons of Indigenous descent in Saskatchewan as 14.7 per 100,000 population. Although we believe that this is an underestimate, this still appears to be the highest population prevalence for SBMA in the world. A total of 21 participants were recruited for the haplotype study, and we identified a unique haplotype that was shared among 13 participants with Indigenous ancestry. A second shared haplotype was identified in 2 participants, which may represent a second founder haplotype, but this would need to be confirmed with future studies.

We describe a very high prevalence of SBMA in western Canadians of Indigenous descent, which appears to predominantly be due to a founder effect. This necessitates further studies of SBMA in these populations to comprehensively ascertain the disease prevalence and allow appropriate allocation of resources to support individuals living with this chronic disease.

脊髓延髓肌萎缩症 (SBMA) 是一种 X 连锁成人发病的神经肌肉疾病，可导致半合子男性进行性虚弱和雄激素不敏感。据报道，这种情况极为罕见，但由于多重创始人效应，在某些人群中的患病率较高。萨斯喀彻温省土著血统患者中 SBMA 患病率较高的轶事观察使我们进行了这项研究，估计疾病患病率，并试图确定创始人效应。

对于我们的患病率估计，我们从萨斯卡通神经肌肉诊所数据库中确定了确诊为 SBMA 的患者，以便与加拿大统计局提供的人口数据进行比较。对于我们的单倍型分析，从 2 个神经肌肉诊所招募了 SBMA 参与者以及 5 名对照参与者。使用唾液试剂盒收集临床数据以及 DNA 样本。我们对 DXS1194、DXS1111、DXS135 和 DXS1125 微卫星重复序列和AR GGC 重复序列进行了靶向定量，以尝试识别疾病单倍型并将其与先前的研究进行比较。

我们估计萨斯喀彻温省土著后裔中 SBMA 的患病率为每 100,000 人中 14.7 人。尽管我们认为这被低估了，但这似乎仍然是世界上 SBMA 的最高人群患病率。总共招募了 21 名参与者进行单倍型研究，我们确定了一种独特的单倍型，该单倍型在 13 名具有土著血统的参与者之间共享。在 2 名参与者中发现了第二个共享单倍型，这可能代表了第二个创始人单倍型，但这需要在未来的研究中得到证实。

我们描述了加拿大西部土著血统的 SBMA 患病率非常高，这似乎主要是由于创始人效应。这需要在这些人群中进一步研究 SBMA，以全面确定疾病流行率并允许适当分配资源以支持患有这种慢性疾病的个人。