Roques I, Pedespan J M, Boisserie-Lacroix V, Ferrer X, Fontan D
Unité de neurologie pédiatrique, hôpital des enfants Pellegrin, Bordeaux, France.
Arch Pediatr. 1998 Aug;5(8):880-3. doi: 10.1016/s0929-693x(98)80131-0.
Germline mosaicism is now well known to account for recurrence of hereditary human disorders. Facioscapulohumeral muscular dystrophy is an autosomal dominant disorder; its locus has been identified in the telomeric region of chromosome 4 at the q35 band. It appears to have a high rate of mutation.
A young girl had presented from childhood signs of a severe form of facioscapulohumeral muscular dystrophy, but with no familial history. The diagnosis was ultimately confirmed at the age of 23 years by molecular studies evidencing the deletion. The same abnormality was sparsely found in the child's father who appeared to harbor the mutation as a germline mosaicism with no clinical expression.
This case illustrates the possibility of severe facioscapulohumeral muscular dystrophy and the dominant transmission of the disorder which may be clinically occult. It underlines the importance of molecular biology and the difficulties of genetic counselling.
种系嵌合现象如今已广为人知，它是人类遗传性疾病复发的原因。面肩肱型肌营养不良症是一种常染色体显性疾病；其基因座已在4号染色体长臂35区带的端粒区域被确定。它似乎具有很高的突变率。
一名年轻女孩自幼就表现出严重形式的面肩肱型肌营养不良症的症状，但无家族病史。最终在其23岁时通过分子研究证实了诊断，该研究发现了相关缺失。在孩子的父亲身上也偶尔发现了相同的异常情况，他似乎作为种系嵌合体携带该突变，但无临床症状。
该病例说明了严重面肩肱型肌营养不良症的可能性以及该疾病可能在临床上隐匿的显性遗传传递方式。它强调了分子生物学的重要性以及遗传咨询的困难。
