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.

van der Sluijs et al [2019]

Gene-targeted deletion/duplication analysis detects intragenic deletions or duplications. Methods used may include a range of techniques such as quantitative PCR, long-range PCR, multiplex ligation-dependent probe amplification (MLPA), and a gene-targeted microarray designed to detect single-exon deletions or duplications.

Microdeletions of chromosome 6q25.3 that include ARID1B have been reported in: (a) children with CSS ascertained prior to the understanding of the molecular basis of CSS [Tsurusaki et al 2012]; (b) children ascertained with a microdeletion containing ARID1B and secondarily noted to have features similar to CSS [Santen et al 2012]; and (c) individuals with mildly or variably syndromic intellectual disability [Nagamani et al 2009, Halgren et al 2012, Hoyer et al 2012, Michelson et al 2012] for whom available clinical information is insufficient to determine the similarity to CSS. Of note, these individuals may have complex clinical findings due to the involvement of additional genes surrounding the ARID1B locus.

Santen et al [2013]

Although the Santen et al [2013] study included sequence analysis results of individuals with clinical features of Coffin-Siris syndrome, it is the only study where all affected individuals underwent both MLPA and sequencing analysis, and therefore likely reflects the mutational spectrum best.

Chromosomal microarray analysis (CMA) uses oligonucleotide or SNP arrays to detect genome-wide large deletions/duplications (including ARID1B) that cannot be detected by sequence analysis. The ability to determine the size of the deletion/duplication depends on the type of microarray used and the density of probes in the 6q25.3 region. CMA designs in current clinical use target the 6q25.3 region.