NM_000817.3:c.83-218C>A

Variant names:

• chr2-170821869-C-A
• rs2241165
• NM_000817.3:c.83-218C>A

Variant summary

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

The NM_000817.3(GAD1):​c.83-218C>A variant causes a intron 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.

• Frequency:
  • Genomes: not found (cov: 34)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: GAD1 NM_000817.3 intron
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -2.38
• Publications: 0 publications found

Genes affected

GAD1 (HGNC:4092): (glutamate decarboxylase 1) This gene encodes one of several forms of glutamic acid decarboxylase, identified as a major autoantigen in insulin-dependent diabetes. The enzyme encoded is responsible for catalyzing the production of gamma-aminobutyric acid from L-glutamic acid. A pathogenic role for this enzyme has been identified in the human pancreas since it has been identified as an autoantigen and an autoreactive T cell target in insulin-dependent diabetes. This gene may also play a role in the stiff man syndrome. Deficiency in this enzyme has been shown to lead to pyridoxine dependency with seizures. Alternative splicing of this gene results in two products, the predominant 67-kD form and a less-frequent 25-kD form. [provided by RefSeq, Jul 2008]

GAD1 Gene-Disease associations (from GenCC):

• early infantile epileptic encephalopathy

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• developmental and epileptic encephalopathy 89

  Inheritance: AR Classification: STRONG, LIMITED Submitted by: G2P, Labcorp Genetics (formerly Invitae)
• spastic quadriplegic cerebral palsy

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• cerebral palsy, spastic quadriplegic, 1

  Inheritance: AR Classification: LIMITED Submitted by: Ambry Genetics
• neurodevelopmental disorder with progressive spasticity and brain white matter abnormalities

  Inheritance: AR Classification: LIMITED Submitted by: 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=-0.79).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000817.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GAD1	NM_000817.3	MANE Select	c.83-218C>A		intron	N/A	NP_000808.2
	GAD1	NM_013445.4		c.83-218C>A		intron	N/A	NP_038473.2

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GAD1	ENST00000358196.8	TSL:1 MANE Select	c.83-218C>A		intron	N/A	ENSP00000350928.3
	GAD1	ENST00000375272.5	TSL:1	c.83-218C>A		intron	N/A	ENSP00000364421.1
	GAD1	ENST00000493875.5	TSL:1	n.83-218C>A		intron	N/A	ENSP00000434696.1

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 419274 Hom.: 0 Cov.: 3 AF XY: 0.00 AC XY: 0 AN XY: 221624

African (AFR) AF: 0.00 AC: 0 AN: 11596

American (AMR) AF: 0.00 AC: 0 AN: 18354

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 12658

East Asian (EAS) AF: 0.00 AC: 0 AN: 28602

South Asian (SAS) AF: 0.00 AC: 0 AN: 44292

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 26704

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 3050

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 249966

Other (OTH) AF: 0.00 AC: 0 AN: 24052

GnomAD4 genome Cov.: 34

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.79
CADD	Benign	0.13
DANN	Benign	0.56
PhyloP100		-2.4
PromoterAI		-0.090	Neutral

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: rs2241165; hg19: chr2-171678379;