3-108355331-T-C

Variant names:

• chr3-108355331-T-C
• rs777243668
• NM_001282556.2:c.635T>C

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_001282556.2(HHLA2):​c.635T>C​(p.Ile212Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000248 in 1,613,778 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 (★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: HHLA2 NM_001282556.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.10
• Publications: 0 publications found

Genes affected

HHLA2 (HGNC:4905): (HHLA2 member of B7 family) This gene encodes a protein ligand found on the surface of monocytes. The encoded protein is thought to regulate cell-mediated immunity by binding to a receptor on T lymphocytes and inhibiting the proliferation of these cells. Alternate splicing results in multiple transcript variants. [provided by RefSeq, Sep 2013]

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.913

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
HHLA2	NM_001282556.2	c.635T>C	p.Ile212Thr	missense_variant	Exon 5 of 10	ENST00000467761.6	NP_001269485.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
HHLA2	ENST00000467761.6	c.635T>C	p.Ile212Thr	missense_variant	Exon 5 of 10	5	NM_001282556.2	ENSP00000419207.1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152194 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.00000403 AC: 1 AN: 248338 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000890

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461584 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727072

African (AFR) AF: 0.00 AC: 0 AN: 33470

American (AMR) AF: 0.00 AC: 0 AN: 44696

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39688

South Asian (SAS) AF: 0.00 AC: 0 AN: 86254

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53398

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000270 AC: 3 AN: 1111804

Other (OTH) AF: 0.00 AC: 0 AN: 60372

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152194 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74350

African (AFR) AF: 0.00 AC: 0 AN: 41448

American (AMR) AF: 0.00 AC: 0 AN: 15272

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3468

East Asian (EAS) AF: 0.00 AC: 0 AN: 5202

South Asian (SAS) AF: 0.00 AC: 0 AN: 4828

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10616

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68042

Other (OTH) AF: 0.00 AC: 0 AN: 2090

Alfa AF: 0.0000312 Hom.: 0

Bravo AF: 0.00000756

ExAC AF: 0.00000828 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Sep 13, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.635T>C (p.I212T) alteration is located in exon 5 (coding exon 3) of the HHLA2 gene. This alteration results from a T to C substitution at nucleotide position 635, causing the isoleucine (I) at amino acid position 212 to be replaced by a threonine (T). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.12
BayesDel_addAF	Benign	-0.020	T
BayesDel_noAF	Benign	-0.27
CADD	Benign	23
DANN	Uncertain	1.0
DEOGEN2	Benign	0.013	T;T;.;T;T;T
Eigen	Benign	-0.035
Eigen_PC	Benign	-0.063
FATHMM_MKL	Benign	0.66	D
LIST_S2	Benign	0.76	T;T;T;.;.;.
M_CAP	Benign	0.0054	T
MetaRNN	Pathogenic	0.91	D;D;D;D;D;D
MetaSVM	Benign	-1.0	T
MutationAssessor	Uncertain	2.4	M;.;.;M;M;M
PhyloP100		2.1
PrimateAI	Benign	0.45	T
PROVEAN	Uncertain	-3.4	.;D;D;D;D;D
REVEL	Benign	0.20
Sift	Uncertain	0.0040	.;D;D;D;D;D
Sift4G	Uncertain	0.0090	D;D;D;D;D;D
Polyphen		0.90	P;P;.;P;P;P
Vest4		0.85
MutPred		0.76		Gain of disorder (P = 0.0124);Gain of disorder (P = 0.0124);.;Gain of disorder (P = 0.0124);Gain of disorder (P = 0.0124);Gain of disorder (P = 0.0124);
MVP		0.46
MPC		0.79
ClinPred		0.93	D
GERP RS		4.5
Varity_R		0.31
gMVP		0.42
Mutation Taster		=92/8	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs777243668; hg19: chr3-108074178;