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تسجيل

Molecular Testing for Spinal Muscular Atrophy

المؤلف:  Cohn, R. D., Scherer, S. W., & Hamosh, A.

المصدر:  Thompson & Thompson Genetics and Genomics in Medicine

الجزء والصفحة:  9th E, P277-278

2026-01-13

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Screening for a missing or deficient exon 7 is the first step in diagnostic testing in patients, with 95% having a homozygous lack of SMN1 exon 7. Several methodologies can detect the absence of SMN1 exon 7, all based on the c.840C>T variation. One of the most popular techniques as a first deletion test in laboratories is multi plex ligation-dependent probe amplification (MLPA). It is simple to use and highly sensitive and can determine both SMN1 and SMN2 copy numbers.

Preimplantation genetic diagnosis and prenatal testing for SMA is available for at-risk couples or due to the presence of abnormal findings on fetal ultrasound, such as decreased fetal movements, contractures in utero, or increased nuchal translucency. The presence of maternal cell contamination of the fetal specimen may result in a false-negative test result and therefore must be tested and shown to be absent prior to reporting the prenatal test result.