2-227363751-G-T

Variant names:

• chr2-227363751-G-T
• NM_024795.4:c.663C>A

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP7

The NM_024795.4(TM4SF20):​c.663C>A​(p.Val221Val) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,616 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: TM4SF20 NM_024795.4 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.308

Genes affected

TM4SF20 (HGNC:26230): (transmembrane 4 L six family member 20) The protein encoded by this gene is a member of the four-transmembrane L6 superfamily. Members of this family function in various cellular processes including cell proliferation, motility, and adhesion via their interactions with integrins. In human brain tissue, this gene is expressed at high levels in the parietal lobe, occipital lobe, hippocampus, pons, white matter, corpus callosum, and cerebellum. Knockout of the homologous gene in mouse results in a neurobehavioral phenotype with suggested enhanced motor coordination. A deletion mutation in the human gene is associated with specific language impairment-5. [provided by RefSeq, Jul 2016]

ACMG classification

Verdict is Likely_benign. Variant got -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.51).
• BP7: Synonymous conserved (PhyloP=0.308 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TM4SF20	NM_024795.4	c.663C>A	p.Val221Val	synonymous_variant	Exon 4 of 4	ENST00000304568.4	NP_079071.2
TM4SF20	XM_011511876.3	c.462C>A	p.Val154Val	synonymous_variant	Exon 5 of 5		XP_011510178.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TM4SF20	ENST00000304568.4	c.663C>A	p.Val221Val	synonymous_variant	Exon 4 of 4	1	NM_024795.4	ENSP00000303028.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461616 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727098

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: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.51
CADD	Benign	2.3
DANN	Benign	0.80

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: chr2-228228467;