Genes are listed in alphabetic order.

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

See Molecular Genetics for information on variants detected in these genes.

Sequence analysis detects variants that are benign, likely benign, of uncertain significance, likely pathogenic, or 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.

Gene-targeted deletion/duplication analysis detects intragenic deletions or duplications. Methods used may include quantitative PCR, long-range PCR, multiplex ligation-dependent probe amplification (MLPA), and a gene-targeted microarray designed to detect single-exon deletions or duplications. Gene-targeted deletion/duplication testing will detect deletions ranging from a single exon to the whole gene; however, breakpoints of large deletions and/or deletion of adjacent genes may not be detected by these methods.

Data derived from the subscription-based professional view of Human Gene Mutation Database [Stenson et al 2017]; Pedrini et al [2011]; W Wuyts, personal communication

Whole-gene, partial-gene, and single-exon deletions have been described but there are no recurrent break points [Jennes et al 2009, Jennes et al 2011, Li et al 2019].

Fusco et al [2019]

It is suspected that simplex cases of HMO harbor a somatic EXT1 or EXT2 pathogenic variant not detected by standard protocols performed on DNA isolated from whole blood samples due to limits of detection [Szuhai et al 2011].