4-47406821-C-A

Variant names:

• chr4-47406821-C-A
• NM_000812.4:c.975C>A
• GABRB1 p.Ala325Ala

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 2P and 3B. PM2 BP4_Moderate BP7

The NM_000812.4(GABRB1):​c.975C>A​(p.Ala325Ala) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. A325A) has been classified as Benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: GABRB1 NM_000812.4 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.472
• Publications: 0 publications found

Genes affected

GABRB1 (HGNC:4081): (gamma-aminobutyric acid type A receptor subunit beta1) The gamma-aminobutyric acid (GABA) A receptor is a multisubunit chloride channel that mediates the fastest inhibitory synaptic transmission in the central nervous system. This gene encodes GABA A receptor, beta 1 subunit. It is mapped to chromosome 4p12 in a cluster comprised of genes encoding alpha 4, alpha 2 and gamma 1 subunits of the GABA A receptor. Alteration of this gene is implicated in the pathogenetics of schizophrenia. [provided by RefSeq, Jul 2008]

GABRB1 Gene-Disease associations (from GenCC):

• developmental and epileptic encephalopathy, 45

  Inheritance: AD Classification: STRONG, MODERATE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
• genetic developmental and epileptic encephalopathy

  Inheritance: AD Classification: LIMITED Submitted by: ClinGen

ACMG classification

Our verdict: Likely_benign. The variant received -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.24).
• BP7: Synonymous conserved (PhyloP=0.472 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000812.4. 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
	GABRB1	NM_000812.4	MANE Select	c.975C>A	p.Ala325Ala	synonymous	Exon 8 of 9	NP_000803.2	X5DNL6

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GABRB1	ENST00000295454.8	TSL:1 MANE Select	c.975C>A	p.Ala325Ala	synonymous	Exon 8 of 9	ENSP00000295454.3	P18505-1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.24
CADD	Benign	7.1
DANN	Benign	0.68
PhyloP100		0.47

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

hg19: chr4-47408838;