17-50186688-C-G

Position:

• chr17-50186688-C-G

Variant summary

Our verdict is Likely pathogenic. Variant got 9 ACMG points: 9P and 0B. PM1 PM2 PP2 PP3_Strong

The NM_000088.4(COL1A1):​c.3766G>C​(p.Ala1256Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A1256T) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: COL1A1 NM_000088.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 7.86

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]

COL1A1 (HGNC:):

ACMG classification

Verdict is Likely_pathogenic. Variant got 9 ACMG points.

• PM1: In a propeptide C-terminal propeptide (size 245) in uniprot entity CO1A1_HUMAN there are 65 pathogenic changes around while only 15 benign (81%) in NM_000088.4
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), COL1A1. . Gene score misZ 3.5319 (greater than the threshold 3.09). Trascript score misZ 5.7733 (greater than threshold 3.09). GenCC has associacion of gene with Caffey disease, Ehlers-Danlos/osteogenesis imperfecta syndrome, combined osteogenesis imperfecta and Ehlers-Danlos syndrome 1, Ehlers-Danlos syndrome, arthrochalasia type, osteogenesis imperfecta type 3, Ehlers-Danlos syndrome, classic type, 1, high bone mass osteogenesis imperfecta, osteogenesis imperfecta type 4, Ehlers-Danlos syndrome, classic type, osteogenesis imperfecta type 2, osteogenesis imperfecta type 1.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.96

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
COL1A1	NM_000088.4	c.3766G>C	p.Ala1256Pro	missense_variant	48/51	ENST00000225964.10	NP_000079.2
COL1A1	XM_011524341.2	c.3568G>C	p.Ala1190Pro	missense_variant	45/48		XP_011522643.1
COL1A1	XM_005257058.5	c.3496G>C	p.Ala1166Pro	missense_variant	46/49		XP_005257115.2
COL1A1	XM_005257059.5	c.2848G>C	p.Ala950Pro	missense_variant	35/38		XP_005257116.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
COL1A1	ENST00000225964.10	c.3766G>C	p.Ala1256Pro	missense_variant	48/51	1	NM_000088.4	ENSP00000225964.6
COL1A1	ENST00000510710.3	n.435G>C		non_coding_transcript_exon_variant	1/2	2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000798 AC: 2 AN: 250554 Hom.: 0 AF XY: 0.0000148 AC XY: 2 AN XY: 135522

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.0000945

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome Cov.: 35

GnomAD4 genome Cov.: 32

ExAC AF: 0.0000165 AC: 2

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.41	D
BayesDel_noAF	Pathogenic	0.36
CADD	Pathogenic	28
DANN	Uncertain	0.99
Eigen	Pathogenic	0.76
Eigen_PC	Uncertain	0.65
FATHMM_MKL	Pathogenic	0.98	D
M_CAP	Pathogenic	0.50	D
MetaRNN	Pathogenic	0.96	D
MetaSVM	Uncertain	0.68	D
PrimateAI	Uncertain	0.74	T
PROVEAN	Pathogenic	-4.6	D
REVEL	Pathogenic	0.93
Sift	Uncertain	0.0010	D
Sift4G	Uncertain	0.0020	D
Vest4		0.95
MutPred		0.83		Gain of glycosylation at A1256 (P = 0.0073);
MVP		0.91
MPC		0.73
ClinPred		0.99	D
GERP RS		3.9
gMVP		0.97

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: rs148216434; hg19: chr17-48264049;