3-49022018-G-C

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PM2 BP4_Strong BS1_Supporting

The ENST00000451378.2(NDUFAF3):c.-95+234G>C variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000485 in 985,652 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.0019 (1 hom., cov: 32)
  • Exomes 𝑓: 0.00022 (0 hom.)
• Consequence: NDUFAF3 ENST00000451378.2 intron
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.0930

Genes affected

NDUFAF3 (HGNC:29918): (NADH:ubiquinone oxidoreductase complex assembly factor 3) This gene encodes a mitochondrial complex I assembly protein that interacts with complex I subunits. Mutations in this gene cause mitochondrial complex I deficiency, a fatal neonatal disorder of the oxidative phosphorylation system. Alternatively spliced transcript variants encoding different isoforms have been identified. [provided by RefSeq, Jul 2009]

DALRD3 (HGNC:25536): (DALR anticodon binding domain containing 3) The exact function of this gene is not known. It encodes a protein with a DALR anticodon binding domain similar to that of class Ia aminoacyl tRNA synthetases. This gene is located in a cluster of genes (with a complex sense-anti-sense genome architecture) on chromosome 3, and contains two micro RNA (miRNA) precursors (mir-425 and mir-191) in one of its introns. Preferential expression of this gene (the miRNAs and other genes in the cluster) in testis suggests a role of this gene in spermatogenesis (PMID:19906709). [provided by RefSeq, Feb 2013]

ACMG classification

Verdict is Likely_benign. Variant got -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.68).
• BS1: Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.00193 (294/152332) while in subpopulation AFR AF= 0.00685 (285/41592). AF 95% confidence interval is 0.0062. There are 1 homozygotes in gnomad4. There are 123 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
NDUFAF3	NM_199070.2	c.-95+234G>C		intron_variant
NDUFAF3	NM_199073.2	c.-94-328G>C		intron_variant
NDUFAF3	NM_199074.2	c.-94-328G>C		intron_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
NDUFAF3	ENST00000451378.2	c.-95+234G>C		intron_variant		1
DALRD3	ENST00000496568.1	c.-347C>G		5_prime_UTR_variant	1/3	2
NDUFAF3	ENST00000326912.8	c.-94-328G>C		intron_variant		2

Frequencies

GnomAD3 genomes AF: 0.00192 AC: 293 AN: 152214 Hom.: 1 Cov.: 32

Gnomad AFR AF: 0.00685

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000458

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.000955

GnomAD4 exome AF: 0.000221 AC: 184 AN: 833320 Hom.: 0 Cov.: 11 AF XY: 0.000193 AC XY: 82 AN XY: 425344

Gnomad4 AFR exome AF: 0.00671

Gnomad4 AMR exome AF: 0.000553

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000102

Gnomad4 OTH exome AF: 0.000512

GnomAD4 genome AF: 0.00193 AC: 294 AN: 152332 Hom.: 1 Cov.: 32 AF XY: 0.00165 AC XY: 123 AN XY: 74486

Gnomad4 AFR AF: 0.00685

Gnomad4 AMR AF: 0.000457

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.000945

Alfa AF: 0.000278 Hom.: 0

Bravo AF: 0.00227

Asia WGS AF: 0.000577 AC: 2 AN: 3478

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Mitochondrial complex I deficiency, nuclear type 1 Uncertain:1

Uncertain significance, 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, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.68
Cadd	Benign	8.0
Dann	Benign	0.72

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: rs74601553; hg19: chr3-49059451;