Genetic Variant NSMF:c.1420-5T>C (chr9-137449679-A-G) – ACMG Classification: Likely_benign (-6 pts)

Variant summary

Our verdict is Likely benign. Variant got -6 ACMG points: 2P and 8B. PM2BP4_StrongBS2

The NM_001130969.3(NSMF):c.1420-5T>C variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000343 in 1,459,522 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 33)

Exomes 𝑓: 0.0000034 ( 0 hom. )

Consequence

NSMF
NM_001130969.3 splice_region, intron

Scores

Splicing: ADA: 0.0001581

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 1.99

Variant links:

Genes affected

NSMF (HGNC:29843): (NMDA receptor synaptonuclear signaling and neuronal migration factor) The protein encoded by this gene is involved in guidance of olfactory axon projections and migration of luteinizing hormone-releasing hormone neurons. Defects in this gene are a cause of idiopathic hypogonadotropic hypogonadism (IHH). Several transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, May 2010]

NSMF links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -6 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.82).

BS2

High AC in GnomAdExome4 at 5 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NSMF	NM_001130969.3 link	c.1420-5T>C		splice_region_variant, intron_variant	Intron 14 of 15	ENST00000371475.9	NP_001124441.1	Q6X4W1-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
NSMF	ENST00000371475.9 link	c.1420-5T>C		splice_region_variant, intron_variant	Intron 14 of 15	1	NM_001130969.3	ENSP00000360530.3		Q6X4W1-1
NSMF	ENST00000371472.6 link	c.1414-5T>C		splice_region_variant, intron_variant	Intron 13 of 15	2		ENSP00000360527.1		Q6X4W1-2

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.0000203

AC:

AN:

246150

Hom.:

AF XY:

0.0000150

AC XY:

AN XY:

133560

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000146

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000343

AC:

AN:

1459522

Hom.:

Cov.:

AF XY:

0.00000276

AC XY:

AN XY:

725928

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.000112

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

Bravo

AF:

0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Mar 18, 2025

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: NSMF c.1414-5T>C alters a non-conserved nucleotide located close to a canonical splice site and therefore could affect mRNA splicing, leading to a significantly altered protein sequence. Consensus agreement among computation tools predict no significant impact on normal splicing. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 2e-05 in 246150 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.1414-5T>C in individuals affected with Hypogonadotropic Hypogonadism 9 With Or Without Anosmia and no experimental evidence demonstrating its impact on protein function have been reported. No submitters have cited clinical-significance assessments for this variant to ClinVar. Based on the evidence outlined above, the variant was classified as uncertain significance. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.82

CADD

Benign

5.5

DANN

Benign

0.63

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Benign

0.00016

dbscSNV1_RF

Benign

0.020

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over