See Table A. Genes and Databases for chromosome locus and protein.

See Molecular Genetics for information on allelic variants.

The ability of the test method used to detect a variant that is present in the indicated gene

The proportion may be higher or lower depending on country or region of origin [van Alfen 2011].

Sequence analysis detects variants that are benign, likely benign, of uncertain significance, likely pathogenic, or pathogenic. Pathogenic variants may include small intragenic deletions/insertions and missense, nonsense, and splice site variants; typically, exon or whole-gene deletions/duplications are not detected. For issues to consider in interpretation of sequence analysis results, click here.

In families with HNA linked to SEPTIN9, sequence analysis identified a sequence variant in 8/42 families [Hannibal et al 2009], a roughly 20% pathogenic variant detection rate.

Testing that identifies exon or whole-gene deletions/duplications not readily detectable by sequence analysis of the coding and flanking intronic regions of genomic DNA. Methods used may include quantitative PCR, long-range PCR, multiplex ligation-dependent probe amplification (MLPA), and chromosomal microarray (CMA) that includes this gene/chromosome segment.

Both a founder duplication and nonrecurrent duplications (with unique breakpoints) have been reported [Landsverk et al 2009, Collie et al 2010]. See Molecular Genetics.

In families with HNA linked to SEPTIN9, CMA identified the founder haplotype duplication in 12/55 families [Landsverk et al 2009] and a tandem duplication in 6/55 families [Collie et al 2010], a roughly 33% variant detection rate.