chr8-144516029-C-A

Variant names:

• chr8-144516029-C-A
• rs144637135
• NM_004260.4:c.1090G>T

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.1090G>T​(p.Val364Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,459,232 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 10/13 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Uncertain significance in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V364M) has been classified as Likely benign.

• 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: 1.06
• Publications: 5 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

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=0.17419705).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
RECQL4	NM_004260.4	c.1090G>T	p.Val364Leu	missense_variant	Exon 5 of 21	ENST00000617875.6	NP_004251.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
RECQL4	ENST00000617875.6	c.1090G>T	p.Val364Leu	missense_variant	Exon 5 of 21	1	NM_004260.4	ENSP00000482313.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1459232 Hom.: 0 Cov.: 66 AF XY: 0.00000138 AC XY: 1 AN XY: 725650

African (AFR) AF: 0.00 AC: 0 AN: 33462

American (AMR) AF: 0.00 AC: 0 AN: 44698

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26102

East Asian (EAS) AF: 0.00 AC: 0 AN: 39658

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86236

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52042

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5764

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1110958

Other (OTH) AF: 0.00 AC: 0 AN: 60312

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 27, 2020

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. This sequence change replaces valine with leucine at codon 364 of the RECQL4 protein (p.Val364Leu). The valine residue is highly conserved and there is a small physicochemical difference between valine and leucine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with RECQL4-related disease. ClinVar contains an entry for this variant (Variation ID: 567838). 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: "Tolerated"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.19
BayesDel_addAF	Benign	-0.0022	T
BayesDel_noAF	Benign	-0.24
CADD	Benign	14
DANN	Benign	0.71
DEOGEN2	Benign	0.085	T;T
FATHMM_MKL	Benign	0.26	N
LIST_S2	Benign	0.71	T;T
M_CAP	Benign	0.0066	T
MetaRNN	Benign	0.17	T;T
PhyloP100		1.1
PrimateAI	Benign	0.39	T
Sift4G	Benign	0.072	T;D
Polyphen		0.96	.;D
Vest4		0.40
MVP		0.32
GERP RS		2.7
PromoterAI		-0.019	Neutral
Varity_R		0.026
gMVP		0.32
Mutation Taster		=92/8	polymorphism

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

Other links and lift over

dbSNP: rs144637135; hg19: chr8-145741413;