2-51027521-G-C

Variant names:

• chr2-51027521-G-C
• rs770481343
• NM_001330078.2:c.753C>G

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP7

The NM_001330078.2(NRXN1):​c.753C>G​(p.Arg251Arg) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000215 in 1,394,412 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. Synonymous variant affecting the same amino acid position (i.e. R251R) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000022 (0 hom.)
• Consequence: NRXN1 NM_001330078.2 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.136
• Publications: 0 publications found

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]

NRXN1 Gene-Disease associations (from GenCC):

• complex neurodevelopmental disorder

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• chromosome 2p16.3 deletion syndrome

  Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• Pitt-Hopkins-like syndrome 2

  Inheritance: AR Classification: STRONG, MODERATE Submitted by: G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae)
• autism

  Inheritance: AD Classification: MODERATE Submitted by: G2P
• schizophrenia

  Inheritance: Unknown Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Likely_benign. The variant received -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.56).
• BP7: Synonymous conserved (PhyloP=-0.136 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NRXN1	NM_001330078.2	c.753C>G	p.Arg251Arg	synonymous_variant	Exon 2 of 23	ENST00000401669.7	NP_001317007.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
NRXN1	ENST00000401669.7	c.753C>G	p.Arg251Arg	synonymous_variant	Exon 2 of 23	5	NM_001330078.2	ENSP00000385017.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000215 AC: 3 AN: 1394412 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 684984

African (AFR) AF: 0.0000942 AC: 3 AN: 31848

American (AMR) AF: 0.00 AC: 0 AN: 38208

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 22108

East Asian (EAS) AF: 0.00 AC: 0 AN: 38646

South Asian (SAS) AF: 0.00 AC: 0 AN: 77124

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 48782

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5384

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1074968

Other (OTH) AF: 0.00 AC: 0 AN: 57344

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.56
CADD	Benign	7.4
DANN	Benign	0.57
PhyloP100		-0.14
PromoterAI		0.075	Neutral
Mutation Taster		=99/1	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs770481343; hg19: chr2-51254659;