12-21470226-C-T

Variant names:

• chr12-21470226-C-T
• NM_002907.4:c.1918G>A

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_002907.4(RECQL):​c.1918G>A​(p.Gly640Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 29)
• Consequence: RECQL NM_002907.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.44

Genes affected

RECQL (HGNC:9948): (RecQ like helicase) The protein encoded by this gene is a member of the RecQ DNA helicase family. DNA helicases are enzymes involved in various types of DNA repair, including mismatch repair, nucleotide excision repair and direct repair. The encoded protein is involved in the processing of Holliday junctions, the suppression of sister chromatid exchanges, telomere maintenance, and is required for genotoxic stress resistance. Defects in this gene have been associated with several types of cancer. [provided by RefSeq, Jan 2017]

PYROXD1 (HGNC:26162): (pyridine nucleotide-disulphide oxidoreductase domain 1) This gene encodes a nuclear-cytoplasmic pyridine nucleotide-disulphide reductase (PNDR). PNDRs are flavoproteins that catalyze the pyridine nucleotide-dependent reduction of thiol residues in other proteins. The encoded protein belongs to the class I pyridine nucleotide-disulphide oxidoreductase family but lacks the C-terminal dimerization domain found in other family members and instead has a C-terminal nitrile reductase domain. It localizes to the nucleus and to striated sarcomeric compartments. Naturally occurring mutations in this gene cause early-onset myopathy with internalized nuclei and myofibrillar disorganization. A pseudogene of this gene has been defined on chromosome 11. [provided by RefSeq, Apr 2017]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.09586251).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
RECQL	NM_002907.4	c.1918G>A	p.Gly640Arg	missense_variant	Exon 15 of 15	ENST00000444129.7	NP_002898.2
PYROXD1	NM_024854.5	c.*1472C>T		3_prime_UTR_variant	Exon 12 of 12	ENST00000240651.14	NP_079130.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
RECQL	ENST00000444129.7	c.1918G>A	p.Gly640Arg	missense_variant	Exon 15 of 15	2	NM_002907.4	ENSP00000416739.2
RECQL	ENST00000421138.6	c.1918G>A	p.Gly640Arg	missense_variant	Exon 16 of 16	1		ENSP00000395449.2
PYROXD1	ENST00000240651.14	c.*1472C>T		3_prime_UTR_variant	Exon 12 of 12	1	NM_024854.5	ENSP00000240651.9
PYROXD1	ENST00000538582.5	c.*1472C>T		3_prime_UTR_variant	Exon 12 of 12	2		ENSP00000438505.1

Frequencies

GnomAD3 genomes Cov.: 29

GnomAD4 exome Cov.: 38

GnomAD4 genome Cov.: 29

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Jul 27, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.G640R variant (also known as c.1918G>A), located in coding exon 14 of the RECQL gene, results from a G to A substitution at nucleotide position 1918. The glycine at codon 640 is replaced by arginine, an amino acid with dissimilar properties. This amino acid position is conserved. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
BayesDel_addAF	Benign	-0.16	T
BayesDel_noAF	Benign	-0.47
CADD	Benign	17
DANN	Uncertain	0.98
DEOGEN2	Benign	0.15	T;T
Eigen	Benign	-0.44
Eigen_PC	Benign	-0.29
FATHMM_MKL	Benign	0.52	D
LIST_S2	Benign	0.74	.;T
M_CAP	Benign	0.0089	T
MetaRNN	Benign	0.096	T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	1.8	L;L
PrimateAI	Benign	0.42	T
PROVEAN	Benign	0.69	N;N
REVEL	Benign	0.070
Sift	Benign	0.21	T;T
Sift4G	Benign	0.20	T;T
Polyphen		0.0	B;B
Vest4		0.22
MutPred		0.21		Loss of methylation at K637 (P = 0.0474);Loss of methylation at K637 (P = 0.0474);
MVP		0.61
MPC		2.0
ClinPred		0.49	T
GERP RS		2.3
Varity_R		0.038
gMVP		0.032

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr12-21623160;