Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PM2PP3PP5_Very_Strong
The NM_201525.4(ADGRG1):c.272G>C(p.Cys91Ser) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,884 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★).
ADGRG1 (HGNC:4512): (adhesion G protein-coupled receptor G1) This gene encodes a member of the G protein-coupled receptor family and regulates brain cortical patterning. The encoded protein binds specifically to transglutaminase 2, a component of tissue and tumor stroma implicated as an inhibitor of tumor progression. Mutations in this gene are associated with a brain malformation known as bilateral frontoparietal polymicrogyria. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Feb 2014]
Verdict is Pathogenic. Variant got 11 ACMG points.
PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.748
PP5
Variant 16-57651407-G-C is Pathogenic according to our data. Variant chr16-57651407-G-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 5832.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
Review Status: criteria provided, single submitter
Collection Method: clinical testing
The C91S pathogenic variant in the ADGRG1 gene has been reported previously as a homozygous variant in an individual with bilateral frontoparietal polymicrogyria (BFPP) (Piao et al., 2004). Functional studies suggest that C91S results in reduced or absent ligand binding of the GPR56 protein (Chiang et al., 2011; Luo et al., 2012). It was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. The C91S variant is a non-conservative amino acid substitution, which is likely to impact secondary protein structure as these residues differ in polarity, charge, size and/or other properties. This substitution occurs at a position that is conserved across species. Therefore, C91S is considered to be a pathogenic variant. -
Apr 07, 2019
Mayo Clinic Laboratories, Mayo Clinic
Significance: Likely pathogenic
Review Status: criteria provided, single submitter