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"With no cure currently available, the best method for preventing SMA iscarrier testing," said Deborah Heine, Executive Director of the Claire AltmanHeine Foundation, a nonprofit organization devoted to promoting pan-ethnic SMAcarrier screening. "The availability of this test will now allow individualsand couples of childbearing age to make more informed reproductive decisionsregarding the risk of SMA and, hopefully, prevent the suffering of losing achild to this devastating disease."
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Deborah and Chris Heine lost their daughter, Claire, to SMA at the age of9 months. The Heines were not offered SMA carrier screening during apre-conception consultation and have worked since that time to implementpan-ethnic SMA carrier screening.
The Genzyme Genetics SMA test offers results in approximately 7 to 11 daysand is expected to have an approximately 94 percent detection rate of carriersoverall and approximately the same detection rate for the most common andsevere types of SMA in affected fetuses. SMA is characterized by progressivemuscle degeneration of motor neurons, resulting in severe muscle weakness. In60-70 percent of cases, children with SMA die from respiratory failure by agetwo.
Greater than 94% of SMA carriers have a deletion of one SMN1 gene.Genzyme's new test utilizes quantitative PCR (polymerase chain reaction), atechnology that can determine the number of SMN1 genes. An individual with oneSMN1 gene is a carrier of SMA; a fetus with no SMN1 genes will be affectedwith SMA. SMA is caused when both parents have only one SMN1 gene.Approximately one in 41 people is a carrier of the SMA-causing gene, resultingin an incidence rate of 1 in 6,000-10,000 births. If both parents are found tobe carriers, prenatal diagnosis by chorionic villi sampling or amniocentesisis available.
"Carriers of SMA have no symptoms of the disease and rarely have a familyhistory of SMA," says Stirling M. Puck, M.D., of Genzyme Genetics. "Therefore,carrier screening for this disease should be widely available to ensure peopleare aware of their chances of having a child with SMA. Advancements intechnology have led to the ability to detect approximately 94 percent ofcarriers, and then to offer prenatal testing to at-risk parents; theseadvancements will help couples planning a pregnancy make informed decisions."
The rights to perform SMN1 testing are provided under license from AthenaDiagnostics, part of Thermo Fisher Scientific Inc.
About SMA
SMA is an autosomal recessive disease which causes severe weakness in themuscles that control breathing, swallowing, head and neck control, walking andcrawling. After cystic fibrosis, which is routinely screened for in thegeneral population, SMA is the second most common lethal autosomal recessivedisease in the United States. Other examples of autosomal recessive conditionsinclude sickle cell anemia, and Tay-Sachs disease.
About Genzyme Genetics
Genzyme Genetics is a leading, nationwide provider of high quality genetictesting and genetic counseling services for physicians and their patients.With laboratories and counseling facilities located across the U.S., GenzymeGenetics offers extensive reproductive and cancer testing services, supportedby innovative technology and a commitment to quality service and trustedinformation. Genzyme Genetics is a business unit of Genzyme Corporation.
