2-231113918-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_000867.5(HTR2B):c.364C>A(p.Pro122Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: HTR2B NM_000867.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 10.0

Genes affected

HTR2B (HGNC:5294): (5-hydroxytryptamine receptor 2B) This gene encodes one of the several different receptors for 5-hydroxytryptamine (serotonin) that belongs to the G-protein coupled receptor 1 family. Serotonin is a biogenic hormone that functions as a neurotransmitter, a hormone, and a mitogen. Serotonin receptors mediate many of the central and peripheral physiologic functions of serotonin, including regulation of cardiovascular functions and impulsive behavior. Population and family-based analyses of a minor allele (glutamine-to-stop substitution, designated Q20*) which blocks expression of this protein, and knockout studies in mice, suggest a role for this gene in impulsivity. However, other factors, such as elevated testosterone levels, may also be involved. Alternatively spliced transcript variants have been found for this gene. [provided by RefSeq, Mar 2016]

PSMD1 (HGNC:9554): (proteasome 26S subunit, non-ATPase 1) The 26S proteasome is a multicatalytic proteinase complex with a highly ordered structure composed of 2 complexes, a 20S core and a 19S regulator. The 20S core is composed of 4 rings of 28 non-identical subunits; 2 rings are composed of 7 alpha subunits and 2 rings are composed of 7 beta subunits. The 19S regulator is composed of a base, which contains 6 ATPase subunits and 2 non-ATPase subunits, and a lid, which contains up to 10 non-ATPase subunits. Proteasomes are distributed throughout eukaryotic cells at a high concentration and cleave peptides in an ATP/ubiquitin-dependent process in a non-lysosomal pathway. An essential function of a modified proteasome, the immunoproteasome, is the processing of class I MHC peptides. This gene encodes the largest non-ATPase subunit of the 19S regulator lid, which is responsible for substrate recognition and binding. There is evidence that this proteasome and its subunits interact with viral proteins, including those of coronaviruses. Alternatively spliced transcript variants have been found for this gene.[provided by RefSeq, Aug 2020]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.886

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
HTR2B	NM_000867.5	c.364C>A	p.Pro122Thr	missense_variant	3/4	ENST00000258400.4
PSMD1	NM_002807.4	c.1884-24818G>T		intron_variant		ENST00000308696.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
HTR2B	ENST00000258400.4	c.364C>A	p.Pro122Thr	missense_variant	3/4	1	NM_000867.5	P1
PSMD1	ENST00000308696.11	c.1884-24818G>T		intron_variant		1	NM_002807.4	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jun 22, 2021

The c.364C>A (p.P122T) alteration is located in exon 3 (coding exon 2) of the HTR2B gene. This alteration results from a C to A substitution at nucleotide position 364, causing the proline (P) at amino acid position 122 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	Pathogenic	0.59
BayesDel_addAF	Pathogenic	0.18	D
BayesDel_noAF	Uncertain	0.020
Cadd	Pathogenic	28
Dann	Uncertain	1.0
DEOGEN2	Uncertain	0.50	T
Eigen	Uncertain	0.67
Eigen_PC	Pathogenic	0.69
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Benign	0.75	T
M_CAP	Benign	0.019	T
MetaRNN	Pathogenic	0.89	D
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	1.9	M
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Uncertain	0.64	T
PROVEAN	Pathogenic	-6.3	D
REVEL	Uncertain	0.46
Sift	Uncertain	0.0020	D
Sift4G	Benign	0.21	T
Polyphen		1.0	D
Vest4		0.88
MutPred		0.58		Loss of helix (P = 0.1299);
MVP		0.85
MPC		0.67
ClinPred		0.98	D
GERP RS		5.2
Varity_R		0.86
gMVP		0.72

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

LitVar

Other links and lift over

dbSNP: rs1695246099; hg19: chr2-231978632;