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

See Molecular Genetics for information on allelic variants detected in this gene.

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.

Data derived from the subscription-based professional view of Human Gene Mutation Database [Stenson et al 2020]

Somatically acquired loss of heterozygosity – for example, due to monosomy 7, del(7q), or uniparental disomy 7 – often occurs in hematopoietic tissue of individuals with a pathogenic SAMD9 variant. SAMD9 is located on chromosome 7 and loss of chromosomes with a pathogenic SAMD9 variant occurs preferentially. This somatic change results in a decreased fraction of cells with the variant and may cause a false negative molecular result when testing leukocyte or bone marrow DNA. Therefore, evaluation of genomic abnormalities with SNP array and/or evaluation of low-abundance variants with deep sequencing (>1000X read depth) should be considered in individuals who are clinically suspected for MIRAGE syndrome and have a negative genetic test result. If feasible, use of DNA derived from non-hematopoietic tissues (e.g. skin fibroblasts, hair roots) may be considered (see Molecular Genetics, SAMD9-specific laboratory technical considerations).

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.

No data on detection rate of gene-targeted deletion/duplication analysis are available. In theory, deletion of SAMD9 would cause loss of function and therefore would not cause MIRAGE syndrome.