1-42747254-C-A

Variant names:

• chr1-42747254-C-A
• rs137853890
• ENST00000397054.7:c.2073G>T

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP7

The NM_001146289.2(P3H1):​c.2073G>T​(p.Ala691Ala) variant causes a splice region, synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,136 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 1/1 splice prediction tools predict no significant impact on normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. A691A) has been classified as Likely pathogenic.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
• Consequence: P3H1 NM_001146289.2 splice_region, synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.150
• Publications: 5 publications found

Genes affected

P3H1 (HGNC:19316): (prolyl 3-hydroxylase 1) This gene encodes an enzyme that is a member of the collagen prolyl hydroxylase family. These enzymes are localized to the endoplasmic reticulum and their activity is required for proper collagen synthesis and assembly. Mutations in this gene are associated with osteogenesis imperfecta type VIII. Three alternatively spliced transcript variants encoding different isoforms have been described. Other variants may exist, but their biological validity has not been determined. [provided by RefSeq, Aug 2011]

P3H1 Gene-Disease associations (from GenCC):

• osteogenesis imperfecta type 8

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae)
• osteogenesis imperfecta type 2

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• osteogenesis imperfecta type 3

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_benign. The variant received -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.59).
• BP7: Synonymous conserved (PhyloP=0.15 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001146289.2. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	P3H1	NM_022356.4	MANE Select	c.2055+18G>T		intron	N/A	NP_071751.3
	P3H1	NM_001243246.2		c.2073G>T	p.Ala691Ala	synonymous	Exon 14 of 14	NP_001230175.1	Q32P28-3
	P3H1	NM_001146289.2		c.2073G>T	p.Ala691Ala	splice_region synonymous	Exon 14 of 15	NP_001139761.1	Q32P28-4

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	P3H1	ENST00000397054.7	TSL:1	c.2073G>T	p.Ala691Ala	splice_region synonymous	Exon 14 of 15	ENSP00000380245.3	Q32P28-4
	P3H1	ENST00000296388.10	TSL:1 MANE Select	c.2055+18G>T		intron	N/A	ENSP00000296388.5	Q32P28-1
	P3H1	ENST00000236040.8	TSL:2	c.2073G>T	p.Ala691Ala	synonymous	Exon 14 of 14	ENSP00000236040.4	Q32P28-3

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152136 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 32

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152136 Hom.: 0 Cov.: 33 AF XY: 0.0000135 AC XY: 1 AN XY: 74316

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 41436

American (AMR) AF: 0.00 AC: 0 AN: 15272

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5198

South Asian (SAS) AF: 0.00 AC: 0 AN: 4824

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10616

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 67998

Other (OTH) AF: 0.00 AC: 0 AN: 2092

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.59
CADD	Benign	3.6
DANN	Benign	0.59
PhyloP100		0.15
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Mutation Taster		=98/2	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.050		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs137853890; hg19: chr1-43212925;