1-186300212-G-C

Variant names:

• chr1-186300212-G-C
• rs61729243
• NM_005807.6:c.198G>C

Variant summary

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

The NM_005807.6(PRG4):​c.198G>C​(p.Ala66Ala) variant causes a splice region, synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,690 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 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. A66A) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: PRG4 NM_005807.6 splice_region, synonymous
• Scores: Splicing: ADA: 0.00005819
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.482
• Publications: 0 publications found

Genes affected

PRG4 (HGNC:9364): (proteoglycan 4) The protein encoded by this gene is a large proteoglycan that is synthesized by chondrocytes located at the surface of articular cartilage and by some synovial lining cells. This protein contains both chondroitin sulfate and keratan sulfate glycosaminoglycans. It functions as a boundary lubricant at the cartilage surface and contributes to the elastic absorption and energy dissipation of synovial fluid. Mutations in this gene result in camptodactyly-arthropathy-coxa vara-pericarditis syndrome. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Dec 2014]

PRG4 Gene-Disease associations (from GenCC):

• camptodactyly-arthropathy-coxa vara-pericarditis syndrome

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: ClinGen, Illumina, Labcorp Genetics (formerly Invitae)

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=-0.64).
• BP7: Synonymous conserved (PhyloP=0.482 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_005807.6. 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
	PRG4	NM_005807.6	MANE Select	c.198G>C	p.Ala66Ala	splice_region synonymous	Exon 3 of 13	NP_005798.3	Q92954-1
	PRG4	NM_001303232.2		c.198G>C	p.Ala66Ala	splice_region synonymous	Exon 3 of 12	NP_001290161.1	Q92954-6
	PRG4	NM_001127709.3		c.198G>C	p.Ala66Ala	splice_region synonymous	Exon 3 of 11	NP_001121181.2	Q92954-3

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PRG4	ENST00000445192.7	TSL:5 MANE Select	c.198G>C	p.Ala66Ala	splice_region synonymous	Exon 3 of 13	ENSP00000399679.3	Q92954-1
	PRG4	ENST00000635041.1	TSL:5	c.198G>C	p.Ala66Ala	splice_region synonymous	Exon 3 of 12	ENSP00000489292.1	Q92954-6
	PRG4	ENST00000367485.4	TSL:5	c.198G>C	p.Ala66Ala	splice_region synonymous	Exon 3 of 11	ENSP00000356455.4	Q92954-3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461690 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727140

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

African (AFR) AF: 0.00 AC: 0 AN: 33468

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86238

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53418

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5630

European-Non Finnish (NFE) AF: 0.00000270 AC: 3 AN: 1111996

Other (OTH) AF: 0.00 AC: 0 AN: 60380

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.64
CADD	Benign	9.8
DANN	Benign	0.89
PhyloP100		0.48
Mutation Taster		=75/25	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.000058
dbscSNV1_RF	Benign	0.0
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

Other links and lift over

dbSNP: rs61729243; hg19: chr1-186269344;