16-30992550-G-T

Variant names:

• chr16-30992550-G-T
• rs138046858
• NM_052874.5:c.*271C>A

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_052874.5(STX1B):​c.*271C>A variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000357 in 280,366 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.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000036 (0 hom.)
• Consequence: STX1B NM_052874.5 3_prime_UTR
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.958
• Publications: 0 publications found

Genes affected

STX1B (HGNC:18539): (syntaxin 1B) The protein encoded by this gene belongs to a family of proteins thought to play a role in the exocytosis of synaptic vesicles. Vesicle exocytosis releases vesicular contents and is important to various cellular functions. For instance, the secretion of transmitters from neurons plays an important role in synaptic transmission. After exocytosis, the membrane and proteins from the vesicle are retrieved from the plasma membrane through the process of endocytosis. Mutations in this gene have been identified as one cause of fever-associated epilepsy syndromes. A possible link between this gene and Parkinson's disease has also been suggested. [provided by RefSeq, Jan 2015]

STX1B Gene-Disease associations (from GenCC):

• generalized epilepsy with febrile seizures plus

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
• generalized epilepsy with febrile seizures plus, type 9

  Inheritance: AD Classification: STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Likely_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.67).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_052874.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	STX1B	NM_052874.5	MANE Select	c.*271C>A		3_prime_UTR	Exon 10 of 10	NP_443106.1	P61266-1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	STX1B	ENST00000215095.11	TSL:1 MANE Select	c.*271C>A		3_prime_UTR	Exon 10 of 10	ENSP00000215095.5	P61266-1
	STX1B	ENST00000916717.1		c.*271C>A		3_prime_UTR	Exon 10 of 10	ENSP00000586776.1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 0.00000357 AC: 1 AN: 280366 Hom.: 0 Cov.: 0 AF XY: 0.00000687 AC XY: 1 AN XY: 145474

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.000118 AC: 1 AN: 8492

American (AMR) AF: 0.00 AC: 0 AN: 9636

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 9186

East Asian (EAS) AF: 0.00 AC: 0 AN: 20914

South Asian (SAS) AF: 0.00 AC: 0 AN: 26942

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 18722

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 1302

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 168160

Other (OTH) AF: 0.00 AC: 0 AN: 17012

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 31

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.67
CADD	Benign	7.4
DANN	Benign	0.67
PhyloP100		0.96

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		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: rs138046858; hg19: chr16-31003871;