OBJECTIVE: To report two cases of spinal muscular atrophy (SMA) after artificial insemination and to discuss why genetic screening of the disease may be justified in gamete donors. DESIGN: Case report. SETTING: Academic departments of genetics and obstetrics. PATIENT(S): A 32-year-old woman with two successive assisted pregnancies. INTERVENTION(S): Molecular studies of the SMN1 (survival motor neuron), the determining gene of the disease. MAIN OUTCOME MEASURE(S); Prenatal testing to detect a homozygous deletion of the SMN1 gene; carrier diagnosis by quantitative analysis to detect a single or double dose of exon 7 in the SMN1 gene. RESULT(S): After a first assisted pregnancy, an SMA child with a homozygous deletion of the SMN1 gene was born. In the second assisted pregnancy, using sperm from a different donor, a fetus with a homozygous deletion of SMN1 was detected. Carrier status in the donor was confirmed by a single dose of SMN1 in the quantitative analysis. CONCLUSION(S): Genetic screening of SMA carrier status by quantitative analysis of the SMN1 gene should be performed in gamete donors when the recipient is a known carrier. Cost-benefit analysis should be made to consider the inclusion of the test in prospective gamete donor programs.
OBJECTIVE: To report two cases of spinal muscular atrophy (SMA) after artificial insemination and to discuss why genetic screening of the disease may be justified in gamete donors. DESIGN: Case report. SETTING: Academic departments of genetics and obstetrics. PATIENT(S): A 32-year-old woman with two successive assisted pregnancies. INTERVENTION(S): Molecular studies of the SMN1 (survival motor neuron), the determining gene of the disease. MAIN OUTCOME MEASURE(S); Prenatal testing to detect a homozygous deletion of the SMN1 gene; carrier diagnosis by quantitative analysis to detect a single or double dose of exon 7 in the SMN1 gene. RESULT(S): After a first assisted pregnancy, an SMA child with a homozygous deletion of the SMN1 gene was born. In the second assisted pregnancy, using sperm from a different donor, a fetus with a homozygous deletion of SMN1 was detected. Carrier status in the donor was confirmed by a single dose of SMN1 in the quantitative analysis. CONCLUSION(S): Genetic screening of SMA carrier status by quantitative analysis of the SMN1 gene should be performed in gamete donors when the recipient is a known carrier. Cost-benefit analysis should be made to consider the inclusion of the test in prospective gamete donor programs.
Authors: Raquel H Barbosa; Fernando R Vargas; Evandro Lucena; Cibele R Bonvicino; Héctor N Seuánez Journal: BMC Med Genet Date: 2009-07-29 Impact factor: 2.103