2-227025788-A-G

Position:

• chr2-227025788-A-G

Variant summary

Our verdict is Benign. Variant got -13 ACMG points: 0P and 13B. BP4_Strong BP6 BS1 BS2

The NM_000092.5(COL4A4):​c.4090+14T>C variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00301 in 1,612,244 control chromosomes in the GnomAD database, including 6 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.0021 (0 hom., cov: 31)
  • Exomes 𝑓: 0.0031 (6 hom.)
• Consequence: COL4A4 NM_000092.5 intron
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:2
• Conservation: PhyloP100: 1.44

Genes affected

COL4A4 (HGNC:2206): (collagen type IV alpha 4 chain) This gene encodes one of the six subunits of type IV collagen, the major structural component of basement membranes. This particular collagen IV subunit, however, is only found in a subset of basement membranes. Like the other members of the type IV collagen gene family, this gene is organized in a head-to-head conformation with another type IV collagen gene so that each gene pair shares a common promoter. Mutations in this gene are associated with type II autosomal recessive Alport syndrome (hereditary glomerulonephropathy) and with familial benign hematuria (thin basement membrane disease). Two transcripts, differing only in their transcription start sites, have been identified for this gene and, as is common for collagen genes, multiple polyadenylation sites are found in the 3' UTR. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Benign. Variant got -13 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.8).
• BP6: Variant 2-227025788-A-G is Benign according to our data. Variant chr2-227025788-A-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 255037.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=1, Benign=1}.
• BS1: Variant frequency is greater than expected in population nfe. gnomad4 allele frequency = 0.00207 (315/152304) while in subpopulation NFE AF= 0.00344 (234/68020). AF 95% confidence interval is 0.00308. There are 0 homozygotes in gnomad4. There are 146 alleles in male gnomad4 subpopulation. Median coverage is 31. This position pass quality control queck.
• BS2: High Homozygotes in GnomAdExome4 at 6 SD gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
COL4A4	NM_000092.5	c.4090+14T>C		intron_variant		ENST00000396625.5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
COL4A4	ENST00000396625.5	c.4090+14T>C		intron_variant		5	NM_000092.5	P1

Frequencies

GnomAD3 genomes AF: 0.00207 AC: 315 AN: 152186 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.000651

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000786

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00207

Gnomad FIN AF: 0.00235

Gnomad MID AF: 0.00316

Gnomad NFE AF: 0.00344

Gnomad OTH AF: 0.00287

GnomAD3 exomes AF: 0.00207 AC: 511 AN: 246460 Hom.: 1 AF XY: 0.00204 AC XY: 274 AN XY: 134046

Gnomad AFR exome AF: 0.000518

Gnomad AMR exome AF: 0.000699

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000557

Gnomad SAS exome AF: 0.00157

Gnomad FIN exome AF: 0.00260

Gnomad NFE exome AF: 0.00321

Gnomad OTH exome AF: 0.00315

GnomAD4 exome AF: 0.00311 AC: 4541 AN: 1459940 Hom.: 6 Cov.: 29 AF XY: 0.00312 AC XY: 2263 AN XY: 726434

Gnomad4 AFR exome AF: 0.000389

Gnomad4 AMR exome AF: 0.000874

Gnomad4 ASJ exome AF: 0.0000766

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.00200

Gnomad4 FIN exome AF: 0.00328

Gnomad4 NFE exome AF: 0.00357

Gnomad4 OTH exome AF: 0.00275

GnomAD4 genome AF: 0.00207 AC: 315 AN: 152304 Hom.: 0 Cov.: 31 AF XY: 0.00196 AC XY: 146 AN XY: 74484

Gnomad4 AFR AF: 0.000649

Gnomad4 AMR AF: 0.000785

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00207

Gnomad4 FIN AF: 0.00235

Gnomad4 NFE AF: 0.00344

Gnomad4 OTH AF: 0.00284

Alfa AF: 0.00208 Hom.: 0

Bravo AF: 0.00169

Asia WGS AF: 0.000577 AC: 2 AN: 3478

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Alport syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 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. -

not specified Benign:1

Likely benign, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

-

- -

not provided Benign:1

Benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 31, 2024

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.80
CADD	Benign	6.2
DANN	Benign	0.64

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs147376687; hg19: chr2-227890504;