2-51027705-T-A

Position:

• chr2-51027705-T-A

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP3

The NM_001330078.2(NRXN1):​c.569A>T​(p.Asn190Ile) variant causes a missense change. 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 (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. N190S) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: NRXN1 NM_001330078.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.96

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 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.82

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
NRXN1	NM_001330078.2	c.569A>T	p.Asn190Ile	missense_variant	2/23	ENST00000401669.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
NRXN1	ENST00000401669.7	c.569A>T	p.Asn190Ile	missense_variant	2/23	5	NM_001330078.2	A1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

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

Invitae

Sep 02, 2019

This sequence change replaces asparagine with isoleucine at codon 190 of the NRXN1 protein (p.Asn190Ile). The asparagine residue is highly conserved and there is a large physicochemical difference between asparagine and isoleucine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with NRXN1-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). 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	Pathogenic	0.95
BayesDel_addAF	Pathogenic	0.20	D
BayesDel_noAF	Uncertain	0.060
CADD	Uncertain	25
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.61	.;D;.;.;T;.;T;D;T;.
Eigen	Uncertain	0.53
Eigen_PC	Uncertain	0.53
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.96	D;D;D;D;D;D;D;D;D;D
M_CAP	Uncertain	0.093	D
MetaRNN	Pathogenic	0.82	D;D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	0.90	D
MutationAssessor	Pathogenic	3.2	M;M;M;.;.;.;.;.;.;.
MutationTaster	Benign	0.98	D;D;D;D;D;D;D
PrimateAI	Uncertain	0.72	T
PROVEAN	Benign	-2.3	.;N;D;D;D;.;.;D;.;.
REVEL	Pathogenic	0.68
Sift	Uncertain	0.0070	.;D;D;D;D;.;.;D;.;.
Sift4G	Pathogenic	0.0	D;D;D;D;D;D;D;D;.;D
Polyphen		0.034, 0.99	.;B;D;.;.;.;.;.;.;.
Vest4		0.85
MutPred		0.63		Loss of disorder (P = 0.047);Loss of disorder (P = 0.047);Loss of disorder (P = 0.047);Loss of disorder (P = 0.047);Loss of disorder (P = 0.047);Loss of disorder (P = 0.047);Loss of disorder (P = 0.047);Loss of disorder (P = 0.047);Loss of disorder (P = 0.047);Loss of disorder (P = 0.047);
MVP		0.65
MPC		1.4
ClinPred		0.96	D
GERP RS		5.3
Varity_R		0.28
gMVP		0.76

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.13		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: rs200792504; hg19: chr2-51254843;