Our verdict is Benign. Variant got -10 ACMG points: 2P and 12B. PM2BP4_StrongBP6_Very_Strong
The NM_133642.5(LARGE1):c.492-8C>T variant causes a splice region, splice polypyrimidine tract, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000124 in 1,613,954 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Likely benign (★★).
LARGE1 (HGNC:6511): (LARGE xylosyl- and glucuronyltransferase 1) This gene encodes a member of the N-acetylglucosaminyltransferase gene family. It encodes a glycosyltransferase which participates in glycosylation of alpha-dystroglycan, and may carry out the synthesis of glycoprotein and glycosphingolipid sugar chains. It may also be involved in the addition of a repeated disaccharide unit. The protein encoded by this gene is the glycotransferase that adds the final xylose and glucuronic acid to alpha-dystroglycan and thereby allows alpha-dystroglycan to bind ligands including laminin 211 and neurexin. Mutations in this gene cause several forms of congenital muscular dystrophy characterized by cognitive disability and abnormal glycosylation of alpha-dystroglycan. Alternative splicing of this gene results in multiple transcript variants that encode the same protein. [provided by RefSeq, May 2018]
PM2 - Absent from controls (or at extremely low frequency if recessive) in Exome Sequencing Project, 1000 Genomes Project, or Exome Aggregation Consortium
Very rare variant in population databases, with high coverage;
BP4
?
BP4 - Multiple lines of computational evidence suggest no impact on gene or gene product (conservation, evolutionary, splicing impact, etc.)
Computational evidence support a benign effect (BayesDel_noAF=-0.77).
BP6
?
BP6 - Reputable source recently reports variant as benign, but the evidence is not available to the laboratory to perform an independent evaluation
Variant 22-33604566-G-A is Benign according to our data. Variant chr22-33604566-G-A is described in ClinVar as [Likely_benign]. Clinvar id is 389225.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
Likely benign, criteria provided, single submitter
clinical testing
GeneDx
Sep 15, 2016
This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -
Muscular dystrophy-dystroglycanopathy type B6 Benign:1
Likely benign, criteria provided, single submitter