1-100187278-A-G

Position:

• chr1-100187278-A-G

Variant summary

Our verdict is Benign. Variant got -14 ACMG points: 0P and 14B. BP4_Strong BP6_Moderate BA1

The NM_001918.5(DBT):​c.*8977T>C variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0223 in 152,258 control chromosomes in the GnomAD database, including 130 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Benign (★).

• Frequency:
  • Genomes: 𝑓 0.022 (130 hom., cov: 32)
  • Failed GnomAD Quality Control
• Consequence: DBT NM_001918.5 3_prime_UTR
• Clinical Significance: Benign criteria provided, single submitter B:1
• Conservation: PhyloP100: -0.721

Genes affected

DBT (HGNC:2698): (dihydrolipoamide branched chain transacylase E2) The branched-chain alpha-keto acid dehydrogenase complex (BCKD) is an inner-mitochondrial enzyme complex involved in the breakdown of the branched-chain amino acids isoleucine, leucine, and valine. The BCKD complex is thought to be composed of a core of 24 transacylase (E2) subunits, and associated decarboxylase (E1), dehydrogenase (E3), and regulatory subunits. This gene encodes the transacylase (E2) subunit. Mutations in this gene result in maple syrup urine disease, type 2. Alternatively spliced transcript variants have been described, but their biological validity has not been determined. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Benign. Variant got -14 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.82).
• BP6: Variant 1-100187278-A-G is Benign according to our data. Variant chr1-100187278-A-G is described in ClinVar as [Benign]. Clinvar id is 291378.Status of the report is criteria_provided_single_submitter, 1 stars.
• BA1: GnomAd4 highest subpopulation (AFR) allele frequency at 95% confidence interval = 0.0747 is higher than 0.05.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
DBT	NM_001918.5	c.*8977T>C		3_prime_UTR_variant	11/11	ENST00000370132.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
DBT	ENST00000370132.8	c.*8977T>C		3_prime_UTR_variant	11/11	1	NM_001918.5	P1

Frequencies

GnomAD3 genomes AF: 0.0222 AC: 3378 AN: 152140 Hom.: 129 Cov.: 32

Gnomad AFR AF: 0.0769

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00897

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000621

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.0127

Gnomad NFE AF: 0.000265

Gnomad OTH AF: 0.0163

GnomAD4 exome Data not reliable, filtered out with message: AC0 AC: 0 AN: 0 Hom.: 0 Cov.: 0 AC XY: 0 AN XY: 0

GnomAD4 genome AF: 0.0223 AC: 3389 AN: 152258 Hom.: 130 Cov.: 32 AF XY: 0.0214 AC XY: 1590 AN XY: 74452

Gnomad4 AFR AF: 0.0770

Gnomad4 AMR AF: 0.00896

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.000207

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.000265

Gnomad4 OTH AF: 0.0161

Alfa AF: 0.0122 Hom.: 11

Bravo AF: 0.0255

Asia WGS AF: 0.00693 AC: 25 AN: 3476

ClinVar

Significance: Benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

Maple syrup urine disease Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.82
CADD	Benign	0.40
DANN	Benign	0.50

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

Publications

LitVar

Other links and lift over

dbSNP: rs113536022; hg19: chr1-100652834;