17-50187128-G-T

Variant summary

Our verdict is Benign. Variant got -9 ACMG points: 0P and 9B. BP4_Strong BP6 BS2

The NM_000088.4(COL1A1):c.3424-6C>A variant causes a splice region, splice polypyrimidine tract, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000329 in 1,597,948 control chromosomes in the GnomAD database, including 4 homozygotes. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.00041 (1 hom., cov: 32)
  • Exomes 𝑓: 0.00032 (3 hom.)
• Consequence: COL1A1 NM_000088.4 splice_region, splice_polypyrimidine_tract, intron
• Scores: Splicing: ADA: 0.001303
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:5
• Conservation: PhyloP100: 0.0300

Genes affected

COL1A1 (HGNC:2197): (collagen type I alpha 1 chain) This gene encodes the pro-alpha1 chains of type I collagen whose triple helix comprises two alpha1 chains and one alpha2 chain. Type I is a fibril-forming collagen found in most connective tissues and is abundant in bone, cornea, dermis and tendon. Mutations in this gene are associated with osteogenesis imperfecta types I-IV, Ehlers-Danlos syndrome type VIIA, Ehlers-Danlos syndrome Classical type, Caffey Disease and idiopathic osteoporosis. Reciprocal translocations between chromosomes 17 and 22, where this gene and the gene for platelet-derived growth factor beta are located, are associated with a particular type of skin tumor called dermatofibrosarcoma protuberans, resulting from unregulated expression of the growth factor. Two transcripts, resulting from the use of alternate polyadenylation signals, have been identified for this gene. [provided by R. Dalgleish, Feb 2008]

ACMG classification

Verdict is Benign. Variant got -9 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.81).
• BP6: Variant 17-50187128-G-T is Benign according to our data. Variant chr17-50187128-G-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 324101.We mark this variant Likely_benign, oryginal submissions are: {Uncertain_significance=1, Benign=3, Likely_benign=2}.
• BS2: High AC in GnomAd at 63 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
COL1A1	NM_000088.4	c.3424-6C>A		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant		ENST00000225964.10
COL1A1	XM_005257058.5	c.3154-6C>A		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant
COL1A1	XM_005257059.5	c.2506-6C>A		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant
COL1A1	XM_011524341.2	c.3226-6C>A		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
COL1A1	ENST00000225964.10	c.3424-6C>A		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant		1	NM_000088.4	P1
COL1A1	ENST00000510710.3			upstream_gene_variant		2

Frequencies

GnomAD3 genomes AF: 0.000414 AC: 63 AN: 152204 Hom.: 1 Cov.: 32

Gnomad AFR AF: 0.0000482

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000654

Gnomad ASJ AF: 0.0127

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.000191

Gnomad OTH AF: 0.00144

GnomAD3 exomes AF: 0.000662 AC: 147 AN: 222048 Hom.: 3 AF XY: 0.000492 AC XY: 59 AN XY: 119876

Gnomad AFR exome AF: 0.0000720

Gnomad AMR exome AF: 0.000263

Gnomad ASJ exome AF: 0.0130

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000910

Gnomad OTH exome AF: 0.00107

GnomAD4 exome AF: 0.000320 AC: 462 AN: 1445626 Hom.: 3 Cov.: 34 AF XY: 0.000281 AC XY: 202 AN XY: 718012

Gnomad4 AFR exome AF: 0.000120

Gnomad4 AMR exome AF: 0.000361

Gnomad4 ASJ exome AF: 0.0134

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000417

Gnomad4 OTH exome AF: 0.000852

GnomAD4 genome AF: 0.000414 AC: 63 AN: 152322 Hom.: 1 Cov.: 32 AF XY: 0.000389 AC XY: 29 AN XY: 74464

Gnomad4 AFR AF: 0.0000481

Gnomad4 AMR AF: 0.0000653

Gnomad4 ASJ AF: 0.0127

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.000191

Gnomad4 OTH AF: 0.00142

Alfa AF: 0.00103 Hom.: 1

Bravo AF: 0.000457

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:5

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Benign:2

Likely benign, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Dec 01, 2022	COL1A1: BP4, BS2 -
Likely benign, criteria provided, single submitter	clinical testing	GeneDx	May 10, 2021	- -

Infantile cortical hyperostosis 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. -

Osteogenesis imperfecta Benign:1

Benign, 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 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. -

Ehlers-Danlos syndrome, arthrochalasia type Benign:1

Benign, 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 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. -

Osteogenesis imperfecta type I Benign:1

Benign, criteria provided, single submitter

clinical testing

Invitae

Jan 22, 2024

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.81
Cadd	Benign	8.6
Dann	Benign	0.80

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.0013
dbscSNV1_RF	Benign	0.054
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: rs370865189; hg19: chr17-48264489;