Providing comprehensive analysis of carrier variants
Popular direct-to-consumer tests look at only 0.01% of your DNA. Using whole genome sequencing (WGS), Genomic Inform™ looks at more than 98% of your DNA. The result is a significantly more complete analysis of your DNA. Including a more complete analysis of carrier variants that have the potential to cause genetic disorders for which screening of expectant mothers is recommended by both the American College of Medical Genetics and Genomics (ACMG) and the American College of Obstetrics and Gynecology (ACOG). As well as other, less frequently screened for disorders.
Cystic fibrosis is a genetic disorder caused by variants in the CFTR gene. The protein produced by this gene is important for maintaining the balance between salt and water on the surface of the lung and other organs of the body. Harmful variants disrupt its function, leading, in the lung, to a buildup of mucus which results in persistent lung infections and makes it difficult to breath. The median age of survival for cystic fibrosis patients is a little over 30 years. Cystic fibrosis is one of the most common inherited disorders. In the US, 1 in 2,500 individuals has the disorder. The most popular direct-to-consumer test screens for 29 variants in the CFTR gene, but with more than 1,700 harmful variants described this covers only a small percentage of known variants.
Influenced by ethnicity, as many as 1 in 25 people are carriers of a CFTR variant.
Thalassemia and related hemoglobinopathies
As many as 1 in 10 individuals of certain ethnicities are carriers of hemoglobinopathy variants.
Hemoglobinopathies are a group of blood disorders that affect red blood cells, resulting in anemia. Common disorders include sickle-cell anemia and beta-thalassemia which are caused by variants in the HBB gene and alpha-thalassemia which is caused by variants in the HBA1 and/or HBA2 genes. HBA1 and HBA2 variants are difficult to detect because the genes are essentially identical. The most popular direct-to-consumer test screens for 10 variants in the HBB gene, but with more than 400 harmful variants described this covers only a small percentage of known variants. Additionally, the sequencing technology that it uses can not distinguish HBA1 and HBA2 variants.
Fragile X syndrome
Fragile X syndrome is one of the most common heritable forms of intellectual disability, occurring in approximately 1 in 4,000 males and 1 in 8,000 females. Patients are most often diagnosed at roughly 3 to 4 years of age after a lengthy period of evaluation and testing. The disorder is caused by expansion of the unstable CGG repeat sequence present in the X-linked FMR1 gene. Individuals with more than 200 repeats are considered to have a full mutation and will be affected. Women who carry repeats ranging in size from 50 to 200 are unlikely to be affected, but are at risk of transmitting a further expanded allele to their children. The risk of further expansion increases with a greater number of repeats. The sequencing technology used by the most popular direct-to-consumer test can not detect FMR1 repeat expansions.
1 in 178 women are carriers of an FMR1 premutation allele.
Spinal muscular atrophy
In most populations, between 1 in 40 and 1 in 60 people are carriers of an SMN1 deletion variant.
Spinal muscular atrophy is a genetic disorder that results in atrophy (weakness and wasting) of the muscles used for movement. There are multiple forms of spinal muscular atrophy, which differ by the severity of symptoms and age of onset. With the most severe forms, patients do not survive beyond infancy. Those patients with less severe forms may live into their 20's or 30's, and patients with the least severe forms have a normal life expectancy. Spinal muscular atrophy is caused by variants in the SMN1 gene. SMN1 variants are difficult to detect because they are often masked from detection through interference by the closely related SMN2 gene. The sequencing technology used by the most popular direct-to-consumer test can not detect SMN1 variants. Note that while the Genomic Inform™ test identifies most carriers of spinal muscular atrophy, it does not identify silent carriers. These are individuals who carry two normal copies of SMN1 on one chromosome and a deletion of SMN1 on the other chromosome. The residual risk of having a negative result but still being a silent carrier ranges from approximately 1 in 800 to 1 in 160 depending on ethnicity.
There are many additional disorders with a high carrier frequency in individuals of Ashkenazi Jewish and other ethnic descents. Yet many of these disorders are not screened for by direct-to-consumer tests. Or if they are, the analysis is incomplete. Genomic Inform™ provides screening for such disorders including, but not limited to:
Beyond providing a more complete analysis of disorders like these, Genomic Inform™ additionally identifies carrier variants for disorders that are not even considered by clinical tests including:
And many more.
Based on whole genome sequencing (WGS) technology, Genomic Inform™ provides comprehensive analysis of carrier mutations for these and thousands of other rare genetic disorders.