8-144513354-A-G

Variant names:

• chr8-144513354-A-G
• rs1554898312
• NM_004260.4:c.2327T>C

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP3

The NM_004260.4(RECQL4):​c.2327T>C​(p.Met776Thr) variant causes a missense change. The variant allele was found at a frequency of 0.00000206 in 1,453,590 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 Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M776I) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: RECQL4 NM_004260.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.07

Genes affected

RECQL4 (HGNC:9949): (RecQ like helicase 4) The protein encoded by this gene is a DNA helicase that belongs to the RecQ helicase family. DNA helicases unwind double-stranded DNA into single-stranded DNAs and may modulate chromosome segregation. This gene is predominantly expressed in thymus and testis. Mutations in this gene are associated with Rothmund-Thomson, RAPADILINO and Baller-Gerold syndromes. [provided by RefSeq, Jan 2010]

ENSG00000265393 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.824

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
RECQL4	NM_004260.4	c.2327T>C	p.Met776Thr	missense_variant	Exon 14 of 21	ENST00000617875.6	NP_004251.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
RECQL4	ENST00000617875.6	c.2327T>C	p.Met776Thr	missense_variant	Exon 14 of 21	1	NM_004260.4	ENSP00000482313.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000206 AC: 3 AN: 1453590 Hom.: 0 Cov.: 48 AF XY: 0.00000276 AC XY: 2 AN XY: 723498

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Baller-Gerold syndrome Uncertain:1

Feb 11, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces methionine with threonine at codon 776 of the RECQL4 protein (p.Met776Thr). The methionine residue is highly conserved and there is a moderate physicochemical difference between methionine and threonine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with a RECQL4-related disease. ClinVar contains an entry for this variant (Variation ID: 459394). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. In summary, this variant has uncertain impact on RECQL4 function. The available evidence is currently insufficient to determine its role in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.94
BayesDel_addAF	Pathogenic	0.37	D
BayesDel_noAF	Pathogenic	0.30
CADD	Uncertain	24
DANN	Benign	0.82
DEOGEN2	Benign	0.27	T;D
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Uncertain	0.97	D;D
M_CAP	Uncertain	0.13	D
MetaRNN	Pathogenic	0.82	D;D
MutationAssessor	Pathogenic	2.9	.;M
PrimateAI	Pathogenic	0.81	D
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	.;D
Vest4		0.83
MVP		0.49
GERP RS		5.7
RBP_binding_hub_radar		0.92
RBP_regulation_power_radar		2.1
Varity_R		0.87
gMVP		0.64

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

LitVar

Other links and lift over

dbSNP: rs1554898312; hg19: chr8-145738737;