7-73705172-G-T

Variant names:

• chr7-73705172-G-T
• NM_004603.4:c.261C>A

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2 PP2

The NM_004603.4(STX1A):​c.261C>A​(p.Asn87Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: STX1A NM_004603.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.83
• Publications: 0 publications found

Genes affected

STX1A (HGNC:11433): (syntaxin 1A) This gene encodes a member of the syntaxin superfamily. Syntaxins are nervous system-specific proteins implicated in the docking of synaptic vesicles with the presynaptic plasma membrane. Syntaxins possess a single C-terminal transmembrane domain, a SNARE [Soluble NSF (N-ethylmaleimide-sensitive fusion protein)-Attachment protein REceptor] domain (known as H3), and an N-terminal regulatory domain (Habc). Syntaxins bind synaptotagmin in a calcium-dependent fashion and interact with voltage dependent calcium and potassium channels via the C-terminal H3 domain. This gene product is a key molecule in ion channel regulation and synaptic exocytosis. Alternatively spliced transcript variants encoding different isoforms have been found for this gene.[provided by RefSeq, Sep 2009]

STX1A Gene-Disease associations (from GenCC):

• complex neurodevelopmental disorder

  Inheritance: AD Classification: MODERATE Submitted by: G2P
• cystic fibrosis

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• neurodevelopmental disorder

  Inheritance: AR Classification: LIMITED Submitted by: G2P

LOC105375350 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 3 curated pathogenic missense variants (we use a threshold of 10). The gene has 0 curated benign missense variants. Gene score misZ: 2.3989 (below the threshold of 3.09). Trascript score misZ: 2.9044 (below the threshold of 3.09). GenCC associations: The gene is linked to cystic fibrosis, complex neurodevelopmental disorder, neurodevelopmental disorder.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
STX1A	NM_004603.4	c.261C>A	p.Asn87Lys	missense_variant	Exon 4 of 10	ENST00000222812.8	NP_004594.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
STX1A	ENST00000222812.8	c.261C>A	p.Asn87Lys	missense_variant	Exon 4 of 10	1	NM_004603.4	ENSP00000222812.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Inborn genetic diseases Uncertain:1

Apr 25, 2025

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.261C>A (p.N87K) alteration is located in exon 4 (coding exon 4) of the STX1A gene. This alteration results from a C to A substitution at nucleotide position 261, causing the asparagine (N) at amino acid position 87 to be replaced by a lysine (K). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.83
BayesDel_addAF	Benign	-0.10	T
BayesDel_noAF	Benign	-0.39
CADD	Pathogenic	26
DANN	Uncertain	0.98
DEOGEN2	Uncertain	0.52	D;.;T;.
Eigen	Benign	-0.053
Eigen_PC	Benign	0.084
FATHMM_MKL	Uncertain	0.85	D
LIST_S2	Uncertain	0.93	D;D;D;D
M_CAP	Benign	0.019	T
MetaRNN	Uncertain	0.60	D;D;D;D
MetaSVM	Benign	-0.99	T
MutationAssessor	Uncertain	2.3	M;M;.;.
PhyloP100		2.8
PrimateAI	Uncertain	0.75	T
PROVEAN	Pathogenic	-5.4	D;D;D;D
REVEL	Benign	0.14
Sift	Benign	0.13	T;T;T;T
Sift4G	Benign	0.11	T;T;T;T
Polyphen		0.0070	B;B;.;.
Vest4		0.64
MutPred		0.49		Loss of ubiquitination at K84 (P = 0.0509);Loss of ubiquitination at K84 (P = 0.0509);Loss of ubiquitination at K84 (P = 0.0509);Loss of ubiquitination at K84 (P = 0.0509);
MVP		0.77
MPC		1.8
ClinPred		0.99	D
GERP RS		4.7
Varity_R		0.70
gMVP		0.65
Mutation Taster		=25/75	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.070		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

hg19: chr7-73119502;