rs1554760875

Variant names:

• chr9-135702340-GAGT-C
• rs1554760875
• NM_020822.3:c.82_85delGAGTinsC

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PM4_Supporting

The NM_020822.3(KCNT1):​c.82_85delGAGTinsC​(p.Glu28_Phe29delinsLeu) variant causes a missense, disruptive inframe deletion change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: KCNT1 NM_020822.3 missense, disruptive_inframe_deletion
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 3.95

Genes affected

KCNT1 (HGNC:18865): (potassium sodium-activated channel subfamily T member 1) Potassium channels represent the most complex class of voltage-gated ion channels from both functional and structural standpoints. Their diverse functions include regulating neurotransmitter release, heart rate, insulin secretion, neuronal excitability, epithelial electrolyte transport, smooth muscle contraction, and cell volume. This gene encodes a sodium-activated potassium channel subunit which is thought to function in ion conductance and developmental signaling pathways. Mutations in this gene cause the early-onset epileptic disorders, malignant migrating partial seizures of infancy and autosomal dominant nocturnal frontal lobe epilepsy. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Dec 2012]

SOHLH1 (HGNC:27845): (spermatogenesis and oogenesis specific basic helix-loop-helix 1) This gene encodes one of testis-specific transcription factors which are essential for spermatogenesis, oogenesis and folliculogenesis. This gene is located on chromosome 9. Mutations in this gene are associated with nonobstructive azoospermia. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Aug 2013]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM4: Nonframeshift variant in NON repetitive region in NM_020822.3. Strenght limited to Supporting due to length of the change: 1aa.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNT1	NM_020822.3	c.82_85delGAGTinsC	p.Glu28_Phe29delinsLeu	missense_variant, disruptive_inframe_deletion	Exon 1 of 31	ENST00000371757.7	NP_065873.2
KCNT1	NM_001272003.2	c.82_85delGAGTinsC	p.Glu28_Phe29delinsLeu	missense_variant, disruptive_inframe_deletion	Exon 1 of 31		NP_001258932.1
SOHLH1	XM_011518698.4	c.-2239_-2236delACTCinsG		upstream_gene_variant			XP_011517000.1
SOHLH1	XM_006717109.5	c.-2368_-2365delACTCinsG		upstream_gene_variant			XP_006717172.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KCNT1	ENST00000371757.7	c.82_85delGAGTinsC	p.Glu28_Phe29delinsLeu	missense_variant, disruptive_inframe_deletion	Exon 1 of 31	1	NM_020822.3	ENSP00000360822.2

Frequencies

GnomAD3 genomes Cov.: 32

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Developmental and epileptic encephalopathy, 14;C3554306:Autosomal dominant nocturnal frontal lobe epilepsy 5 Uncertain:1

Sep 15, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Experimental studies and prediction algorithms are not available for this variant, and the functional significance of the disrupted amino acids is currently unknown. This variant has not been reported in the literature in individuals with KCNT1-related disease. This variant is not present in population databases (ExAC no frequency). This variant, c.82_84delGAG, results in the deletion of 1 amino acid(s) of the KCNT1 protein (p.Glu28del), but otherwise preserves the integrity of the reading frame. -

not provided Uncertain:1

Dec 28, 2021

Athena Diagnostics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Splicing

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

Publications

LitVar

Other links and lift over

dbSNP: rs1554760875; hg19: chr9-138594186;