Helbling-Leclerc A, Topaloglu H, Tomé F M, Sewry C, Gyapay G, Naom I, Muntoni F, Dubowitz V, Barois A, Estournet B
INSERM U. 153, hôpital Pitié-Salpêtrière, Paris, France.
C R Acad Sci III. 1995 Dec;318(12):1245-52.
The laminin alpha 2-chain gene mutations (LAMA2) are responsible for about 50% of the cases of classical congenital muscular dystrophy. These patients form a clinically homogenous group presenting merosin (laminin alpha 2-chain) deficiency in muscle biopsies. The LAMA2 gene has been previously localized on 6q22-23 and the disease locus mapped in a 16 cM interval in 6q2 by homozygosity mapping. In the present report we establish, by haplotyping additional microsatellites markers in 18 consanguineous families, that LAMA2 gene is more centromeric than previously thought: between the flanking markers, D6S407 and D6S1705, distant of 3 cM. In this interval the microsatellite D6S1620 is homozygous for all the patients. The localization of LAMA2 gene was confirmed by radiation hybrid mapping. The 3 new highly informative markers can be very useful for prenatal diagnosis.
层粘连蛋白α2链基因突变（LAMA2）约占经典型先天性肌营养不良病例的50%。这些患者构成了一个临床同质性群体，肌肉活检显示出现merosin（层粘连蛋白α2链）缺乏。LAMA2基因先前已定位在6q22 - 23，通过纯合性定位将疾病位点定位在6q的一个16厘摩区间内。在本报告中，我们通过对18个近亲家庭中的其他微卫星标记进行单倍型分析，确定LAMA2基因比先前认为的更靠近着丝粒：在侧翼标记D6S407和D6S1705之间，相距3厘摩。在这个区间内，微卫星D6S1620在所有患者中都是纯合的。通过辐射杂种图谱证实了LAMA2基因的定位。这3个新的高信息性标记对产前诊断可能非常有用。
