8-144513431-G-C

Variant names:

• chr8-144513431-G-C
• rs761639839
• NM_004260.4:c.2250C>G

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_004260.4(RECQL4):​c.2250C>G​(p.Ser750Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000686 in 1,457,224 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 9/13 in silico tools predict a benign 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. S750I) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: RECQL4 NM_004260.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.03
• Publications: 0 publications found

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]

RECQL4 Gene-Disease associations (from GenCC):

• Baller-Gerold syndrome

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: PanelApp Australia, G2P, Orphanet
• Rothmund-Thomson syndrome

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• Rothmund-Thomson syndrome type 2

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, Genomics England PanelApp, G2P
• osteosarcoma

  Inheritance: AR Classification: STRONG Submitted by: Genomics England PanelApp
• rapadilino syndrome

  Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Genomics England PanelApp

ENSG00000265393 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.17449486).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_004260.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	RECQL4	NM_004260.4	MANE Select	c.2250C>G	p.Ser750Arg	missense	Exon 14 of 21	NP_004251.4
	RECQL4	NM_001413019.1		c.2250C>G	p.Ser750Arg	missense	Exon 14 of 20	NP_001399948.1
	RECQL4	NM_001413036.1		c.2250C>G	p.Ser750Arg	missense	Exon 14 of 21	NP_001399965.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	RECQL4	ENST00000617875.6	TSL:1 MANE Select	c.2250C>G	p.Ser750Arg	missense	Exon 14 of 21	ENSP00000482313.2
	RECQL4	ENST00000621189.4	TSL:1	c.1179C>G	p.Ser393Arg	missense	Exon 13 of 20	ENSP00000483145.1
	RECQL4	ENST00000534626.6	TSL:5	c.618C>G	p.Ser206Arg	missense	Exon 5 of 8	ENSP00000477457.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.86e-7 AC: 1 AN: 1457224 Hom.: 0 Cov.: 47 AF XY: 0.00 AC XY: 0 AN XY: 725116

African (AFR) AF: 0.00 AC: 0 AN: 33472

American (AMR) AF: 0.00 AC: 0 AN: 44676

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26112

East Asian (EAS) AF: 0.00 AC: 0 AN: 39696

South Asian (SAS) AF: 0.00 AC: 0 AN: 86234

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 49208

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111740

Other (OTH) AF: 0.00 AC: 0 AN: 60320

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

Jan 15, 2020

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0"). 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: 459390). This variant is not present in population databases (ExAC no frequency). This sequence change replaces serine with arginine at codon 750 of the RECQL4 protein (p.Ser750Arg). The serine residue is moderately conserved and there is a moderate physicochemical difference between serine and arginine.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.36
BayesDel_addAF	Benign	-0.011	T
BayesDel_noAF	Benign	-0.25
CADD	Benign	16
DANN	Benign	0.63
DEOGEN2	Benign	0.071	T
FATHMM_MKL	Benign	0.30	N
LIST_S2	Uncertain	0.90	D
M_CAP	Benign	0.0031	T
MetaRNN	Benign	0.17	T
PhyloP100		1.0
PrimateAI	Benign	0.47	T
Sift4G	Benign	0.088	T
Polyphen		0.34	B
Vest4		0.19
MVP		0.74
GERP RS		2.4
Varity_R		0.16
gMVP		0.48
Mutation Taster		=91/9	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs761639839; hg19: chr8-145738815;