Associated disorders

The GMPPB gene is associated with autosomal recessive muscular dystrophy-dystroglycanopathy type A14 (MDDGA14) (MedGen UID: 815546), type B14 (MDDGB14) (MedGen UID: 815551) and type C14 (MDDGC14) (MedGen UID: 811507). Additionally, the GMPPB gene has preliminary evidence supporting a correlation with autosomal recessive congenital myasthenic syndrome (CMS) (PMID: 26133662).

Pathogenic variants in GMPPB cause an unknown percentage of muscular dystrophy-dystroglycanopathy and congenital myasthenic syndromes.

The GMPPB gene encodes the GDP-mannose pyrophosphorylase beta subunit, a component of GDP-mannose pyrophosphorylase. This enzyme catalyzes the synthesis of GDP-mannose, which is required in multiple glycosylation pathways.

Assay and technical information

Invitae is a College of American Pathologists (CAP)-accredited and Clinical Laboratory Improvement Amendments (CLIA)-certified clinical diagnostic laboratory performing full-gene sequencing and deletion/duplication analysis using next-generation sequencing technology (NGS).

Our sequence analysis covers clinically important regions of each gene, including coding exons, +/- 10 base pairs of adjacent intronic sequence, and select noncoding variants. Our assay provides a Q30 quality-adjusted mean coverage depth of 350x (50x minimum, or supplemented with additional analysis). Variants classified as pathogenic or likely pathogenic are confirmed with orthogonal methods, except individual variants that have high quality scores and previously validated in at least ten unrelated samples.

Our analysis detects most intragenic deletions and duplications at single exon resolution. However, in rare situations, single-exon copy number events may not be analyzed due to inherent sequence properties or isolated reduction in data quality. If you are requesting the detection of a specific single-exon copy number variation, please contact Client Services before placing your order.

Gene Transcript reference Sequencing analysis Deletion/Duplication analysis
GMPPB NM_021971.2