2-50506509-T-G

Position:

• chr2-50506509-T-G

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NM_001330078.2(NRXN1):​c.2483A>C​(p.Gln828Pro) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: NRXN1 NM_001330078.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.36

Genes affected

NRXN1 (HGNC:8008): (neurexin 1) This gene encodes a single-pass type I membrane protein that belongs to the neurexin family. Neurexins are cell-surface receptors that bind neuroligins to form Ca(2+)-dependent neurexin/neuroligin complexes at synapses in the central nervous system. This complex is required for efficient neurotransmission and is involved in the formation of synaptic contacts. Three members of this gene family have been studied in detail and are estimated to generate over 3,000 variants through the use of two alternative promoters (alpha and beta) and extensive alternative splicing in each family member. Recently, a third promoter (gamma) was identified for this gene in the 3' region. Mutations in this gene are associated with Pitt-Hopkins-like syndrome-2 and may contribute to susceptibility to schizophrenia. [provided by RefSeq, Aug 2016]

ACMG classification

Verdict is Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.38231626).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
NRXN1	NM_001330078.2	c.2483A>C	p.Gln828Pro	missense_variant	13/23	ENST00000401669.7	NP_001317007.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
NRXN1	ENST00000401669.7	c.2483A>C	p.Gln828Pro	missense_variant	13/23	5	NM_001330078.2	ENSP00000385017	A1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Pitt-Hopkins-like syndrome 2 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Sep 22, 2016

This sequence change replaces glutamine with proline at codon 868 of the NRXN1 protein (p.Gln868Pro). The glutamine residue is highly conserved and there is a moderate physicochemical difference between glutamine and proline. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a NRXN1-related disease. 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: "Possibly Damaging"; Align-GVGD: "Class C0"). In summary, this variant is a novel missense change with uncertain impact on protein function. It has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.33
BayesDel_addAF	Uncertain	0.036	T
BayesDel_noAF	Benign	-0.19
CADD	Pathogenic	28
DANN	Uncertain	0.99
DEOGEN2	Benign	0.28	.;T;.;.;T;.;.;T
Eigen	Benign	0.18
Eigen_PC	Uncertain	0.24
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Uncertain	0.89	D;D;D;D;D;D;D;D
M_CAP	Benign	0.045	D
MetaRNN	Benign	0.38	T;T;T;T;T;T;T;T
MetaSVM	Benign	-0.66	T
MutationAssessor	Benign	0.90	.;L;.;.;.;.;.;.
MutationTaster	Benign	0.95	N;N;N;N;N;N
PrimateAI	Uncertain	0.62	T
PROVEAN	Benign	-0.83	.;N;N;N;.;.;.;.
REVEL	Uncertain	0.43
Sift	Benign	0.18	.;T;T;T;.;.;.;.
Sift4G	Benign	0.094	T;T;T;T;T;T;T;T
Polyphen		0.86	.;.;P;.;.;.;.;.
Vest4		0.62
MutPred		0.59		.;Loss of MoRF binding (P = 0.0783);.;Loss of MoRF binding (P = 0.0783);.;.;.;.;
MVP		0.068
MPC		0.66
ClinPred		0.62	D
GERP RS		4.5
Varity_R		0.42
gMVP		0.82

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.040		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: rs1060503177; hg19: chr2-50733647;