2-49919109-A-G

Variant names:

• chr2-49919109-A-G
• rs553997030
• NM_001330078.2:c.*2835T>C

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 0P and 3B. BP4_Moderate BS1_Supporting

The NM_001330078.2(NRXN1):​c.*2835T>C variant causes a 3 prime UTR change. The variant allele was found at a frequency of 0.00257 in 152,270 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: 𝑓 0.0026 (1 hom., cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: NRXN1 NM_001330078.2 3_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 4.01
• 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.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.45).
• BS1: Variant frequency is greater than expected in population nfe. GnomAd4 allele frequency = 0.00257 (392/152270) while in subpopulation NFE AF = 0.00461 (313/67964). AF 95% confidence interval is 0.00418. There are 1 homozygotes in GnomAd4. There are 160 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NRXN1	NM_001330078.2	c.*2835T>C		3_prime_UTR_variant	Exon 23 of 23	ENST00000401669.7	NP_001317007.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
NRXN1	ENST00000401669.7	c.*2835T>C		3_prime_UTR_variant	Exon 23 of 23	5	NM_001330078.2	ENSP00000385017.2

Frequencies

GnomAD3 genomes AF: 0.00258 AC: 392 AN: 152152 Hom.: 1 Cov.: 32

Gnomad AFR AF: 0.00111

Gnomad AMI AF: 0.00439

Gnomad AMR AF: 0.000393

Gnomad ASJ AF: 0.00115

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00160

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00460

Gnomad OTH AF: 0.000956

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 6 Hom.: 0 Cov.: 0 AF XY: 0.00 AC XY: 0 AN XY: 4

African (AFR) AC: 0 AN: 0

American (AMR) AC: 0 AN: 0

Ashkenazi Jewish (ASJ) AC: 0 AN: 0

East Asian (EAS) AC: 0 AN: 0

South Asian (SAS) AC: 0 AN: 0

European-Finnish (FIN) AC: 0 AN: 0

Middle Eastern (MID) AC: 0 AN: 0

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 4

Other (OTH) AF: 0.00 AC: 0 AN: 2

GnomAD4 genome AF: 0.00257 AC: 392 AN: 152270 Hom.: 1 Cov.: 32 AF XY: 0.00215 AC XY: 160 AN XY: 74444

African (AFR) AF: 0.00111 AC: 46 AN: 41584

American (AMR) AF: 0.000392 AC: 6 AN: 15298

Ashkenazi Jewish (ASJ) AF: 0.00115 AC: 4 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5180

South Asian (SAS) AF: 0.00 AC: 0 AN: 4832

European-Finnish (FIN) AF: 0.00160 AC: 17 AN: 10622

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.00461 AC: 313 AN: 67964

Other (OTH) AF: 0.000946 AC: 2 AN: 2114

Alfa AF: 0.00191 Hom.: 0

Bravo AF: 0.00240

Asia WGS AF: 0.000289 AC: 1 AN: 3476

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:1

-

Breakthrough Genomics, Breakthrough Genomics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: not provided

- -

Pitt-Hopkins-like syndrome 2 Uncertain:1

Jan 12, 2018

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.45
CADD	Benign	11
DANN	Benign	0.66
PhyloP100		4.0

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs553997030; hg19: chr2-50146247;