8. Recessive Compound HeterozygousΒΆ

A compound heterozygous polymorphism refers to a child that has inherited two different heterozygous polymorphisms within the same gene, one from each parent. This could result in both copies of the gene being potentially affected. This type of polymorphism should also alter the amino acid sequence, or be classified as a non-synonymous variant. The unique filter card implements the Compound Het algorithm, which can be found by going to Add>Computed Data>Compound Het. It is important to note that this algorithm is computed on the variants in the selected filter chain and not all variants orginally imported.

Compound het

Figure 8-1: The compound het algorithm determines inheritance of two different heterozygous polymorphisms within the same gene.

Using the Auto Classification, Compound Het algorithm and Gene Inheritance filter logic identified 16 variants. To see further specifics, click on the Compound Het Genes table, next to the variant table tab. In the left dialog you can see the Gene Names and if the gene has a compound het polymorphism, as well as the variant information in the right dialog. If you click on a gene in the Gene Name column, the variant table will display the variants that fall within that gene. For example, if you click on the Gene Name: ANKRD36, you can see that this gene has three variants, one De novo variant and two heterozygous mutatons inherited from the mother. Once finished, change the display back to the Variant table tab, Variants: 16.

Compound het genes

Figure 8-2: Opening the Compound Het Gene table displays affected genes and associated variants.