chr8-144516197-G-A

Variant names:

• chr8-144516197-G-A
• rs756016498
• NM_004260.4:c.922C>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.922C>T​(p.Pro308Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000479 in 1,461,068 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 variant affecting the same amino acid position, but resulting in a different missense (i.e. P308T) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 34)
  • Exomes 𝑓: 0.0000048 (0 hom.)
• Consequence: RECQL4 NM_004260.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.0540
• 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

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=0.1187996).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
RECQL4	NM_004260.4	c.922C>T	p.Pro308Ser	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.922C>T	p.Pro308Ser	missense_variant	Exon 5 of 21	1	NM_004260.4	ENSP00000482313.2

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome AF: 0.00000479 AC: 7 AN: 1461068 Hom.: 0 Cov.: 66 AF XY: 0.00000550 AC XY: 4 AN XY: 726798

African (AFR) AF: 0.00 AC: 0 AN: 33476

American (AMR) AF: 0.00 AC: 0 AN: 44718

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52830

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5746

European-Non Finnish (NFE) AF: 0.00000630 AC: 7 AN: 1111850

Other (OTH) AF: 0.00 AC: 0 AN: 60356

GnomAD4 genome Cov.: 34

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Baller-Gerold syndrome Uncertain:1

Oct 23, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces proline, which is neutral and non-polar, with serine, which is neutral and polar, at codon 308 of the RECQL4 protein (p.Pro308Ser). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with RECQL4-related conditions. ClinVar contains an entry for this variant (Variation ID: 2070928). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt RECQL4 protein function. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.069
BayesDel_addAF	Benign	-0.13	T
BayesDel_noAF	Benign	-0.43
CADD	Benign	4.4
DANN	Benign	0.79
DEOGEN2	Benign	0.035	T
FATHMM_MKL	Benign	0.097	N
LIST_S2	Benign	0.43	T
M_CAP	Benign	0.0030	T
MetaRNN	Benign	0.12	T
PhyloP100		0.054
PrimateAI	Benign	0.24	T
Sift4G	Benign	0.34	T
Polyphen		0.65	P
Vest4		0.14
MVP		0.74
GERP RS		0.40
PromoterAI		-0.0047	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.029
gMVP		0.21
Mutation Taster		=99/1	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: rs756016498; hg19: chr8-145741581;