17-50197767-C-G

Variant names:

• chr17-50197767-C-G
• NM_000088.4:c.661G>C

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PM1 PM2 PM5 PP2 PP3_Strong PP5

The NM_000088.4(COL1A1):​c.661G>C​(p.Gly221Arg) 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. 11/19 in silico tools predict a damaging outcome for this variant. Variant has been reported in Lovd as Pathogenic (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G221A) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: COL1A1 NM_000088.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 7.91

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 Pathogenic. Variant got 12 ACMG points.

• PM1: In a compositionally_biased_region Pro residues (size 43) in uniprot entity CO1A1_HUMAN there are 83 pathogenic changes around while only 2 benign (98%) in NM_000088.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr17-50197766-C-G is described in Lovd as [Pathogenic].
• PP2: Missense variant in the COL1A1 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 368 curated pathogenic missense variants (we use a threshold of 10). The gene has 98 curated benign missense variants. Gene score misZ: 3.5319 (above the threshold of 3.09). Trascript score misZ: 5.7733 (above the threshold of 3.09). GenCC associations: The gene is linked to 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, 0.994
• PP5: Variant 17-50197767-C-G is Pathogenic according to our data. Variant chr17-50197767-C-G is described in Lovd as [Pathogenic]. Variant chr17-50197767-C-G is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
COL1A1	NM_000088.4	c.661G>C	p.Gly221Arg	missense_variant	Exon 9 of 51	ENST00000225964.10	NP_000079.2
COL1A1	XM_011524341.2	c.661G>C	p.Gly221Arg	missense_variant	Exon 9 of 48		XP_011522643.1
COL1A1	XM_005257058.5	c.661G>C	p.Gly221Arg	missense_variant	Exon 9 of 49		XP_005257115.2
COL1A1	XM_005257059.5	c.661G>C	p.Gly221Arg	missense_variant	Exon 9 of 38		XP_005257116.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
COL1A1	ENST00000225964.10	c.661G>C	p.Gly221Arg	missense_variant	Exon 9 of 51	1	NM_000088.4	ENSP00000225964.6
COL1A1	ENST00000495677.1	n.388G>C		non_coding_transcript_exon_variant	Exon 4 of 8	3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.59
CADD	Pathogenic	27
DANN	Uncertain	1.0
Eigen	Pathogenic	0.97
Eigen_PC	Pathogenic	0.84
FATHMM_MKL	Uncertain	0.96	D
M_CAP	Pathogenic	0.97	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	0.94	D
PrimateAI	Pathogenic	0.93	D
PROVEAN	Pathogenic	-6.3	D
REVEL	Pathogenic	0.99
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0010	D
Vest4		0.99
MutPred		0.99		Loss of methylation at R220 (P = 0.04);
MVP		1.0
MPC		0.67
ClinPred		1.0	D
GERP RS		4.8
gMVP		0.99

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr17-48275128;