背景:双尾D同源物2(BICD2)是常染色体显性下肢显性脊髓性肌萎缩症2(SMA-LED2)的致病基因。SMA-LED2的严重程度差异很大,从患者能够行走的病例到严重关节挛缩导致呼吸衰竭的病例。在这项研究中,我们报告了1例SMA-LED2的长期病程,并与以往的报告进行了比较.
方法:患者为19岁女性。她膝盖和髋部脱位伴有挛缩,股骨骨折,和跟骨外翻从出生开始,并被诊断为多发性先天性关节炎。在新生儿期不需要强烈的呼吸支持。她反复得了吸入性肺炎,必须在8个月大之前入住NICU。她在9个月大时实现了头部控制,并且能够在2岁时坐着;但是,她不能走路。需要管饲直到3岁。目前,她可以口服,带着轮椅四处走动,自己写单词。由于青春期的限制性呼吸系统疾病,她在睡眠期间需要无创正压通气。外显子组分析鉴定了BICD2中的从头杂合错义变体(c.2320G>A;p.Glu774Lys)。
结论:与新生儿期的功能障碍相比,SMA-LED2患者在社会活动方面的预后可能相对更好。此外,定期评估SMA-LED2患者的呼吸功能非常重要,因为呼吸功能障碍可能发生在青春期.
BACKGROUND: Bicaudal D homolog 2 (BICD2) is a causative gene of autosomal-dominant lower extremity-predominant spinal muscular atrophy-2 (SMA-LED2). The severity of SMA-LED2 varies widely, ranging from cases in which patients are able to walk to cases in which severe joint contractures lead to respiratory failure. In this study, we report the long-term course of a case of SMA-LED2 in comparison with previous reports.
METHODS: The patient was a 19-year-old woman. She had knee and hip dislocations with contractures, femoral fracture, and talipes calcaneovalgus since birth, and was diagnosed with arthrogryposis multiplex congenita. Intense respiratory support was not needed during the neonatal period. She had aspiration pneumonia repeatedly, necessitating NICU admission until 8 months of age. She achieved head control at 9 months of age and was able to sit at 2 years of age; however, she could not walk. Tube feeding was required until 3 years of age. At present, she can eat orally, move around with a wheelchair, and write words by herself. She needs non-invasive positive pressure ventilation during sleep because of a restrictive respiratory disorder during adolescence. Exome analysis identified a de novo heterozygous missense variant (c.2320G>A; p.Glu774Lys) in BICD2.
CONCLUSIONS: Patients with SMA-LED2 may have a relatively better prognosis in terms of social activities in comparison with the dysfunction in the neonatal period. Moreover, it is important to periodically evaluate respiratory function in patients with SMA-LED2 because respiratory dysfunction may occur during adolescence.