Single-gene carrier screening

Spinal muscular atrophy

In addition to a comprehensive screening test for more than 500 genetic disorders (Inheritest), we also offer screening for specific disorders, such as spinal muscular atrophy (SMA), the most common inherited cause of early childhood mortality.1 With more than 600,000 tested samples, Integrated Genetics has been a leader in the field of SMA research and testing.

Screening for Spinal muscular atrophy

Because of the severity and relatively high carrier frequency, there has been increasing interest in carrier screening for SMA in the general prenatal population. “Screening for spinal muscular atrophy should be offered to all women who are considering pregnancy or are currently pregnant.” – ACOG Committee Opinion No. 691, March 2017.

As with most inherited disorders, the risk for being an SMA carrier varies by ethnic background.2

EthnicitySMA carrier risk
Caucasian1:47
Ashkenazi Jewish1:67
Asian1:59
Hispanic1:68
Asian Indian1:52
African American1:72

Mixed ethnicities for counseling purposes, consider using the ethnic background with the most conservative risk.

Determine if the baby is affected

For pregnancies at risk, we also offer prenatal testing to determine whether the baby has the parental mutations, saving patients time and additional testing.

Sample requirement and turnaround time

The screening test requires a blood sample and results are typically ready within five to eight days. If a couple has not yet conceived, one partner is usually tested first. If a woman is already pregnant, a couple may opt to be tested at the same time.

Additional Resources

References

  1. Carrier Screening for Genetic Conditions. ACOG Committee Opinion No. 691, March 2017
  2. Sugarman EA, et al. Pan-ethnic carrier screening and prenatal diagnosis for spinal muscular atrophy: clinical laboratory analysis of >72,400 specimens. Eur J Hum Genet 2012; 20:27-32.
  3. Dombrowski C et al, Premutation and intermediate-size FMR1 alleles in 10572 males from the general population: loss of an AGG interruption is a late event in the generation of fragile X syndrome alleles. Hum Mol Genet. 2002 11(4):371-8