chr2-26430878-G-A

Variant names:

• chr2-26430878-G-A
• rs374715318
• NM_145038.5:c.765+6G>A

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BP4_Strong

The NM_145038.5(DRC1):​c.765+6G>A variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000211 in 1,613,636 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. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000021 (0 hom.)
• Consequence: DRC1 NM_145038.5 splice_region, intron
• Scores: Splicing: ADA: 0.001372
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.683
• Publications: 0 publications found

Genes affected

DRC1 (HGNC:24245): (dynein regulatory complex subunit 1) This gene encodes a central component of the nexin-dynein complex (N-DRC), which regulates the assembly of ciliary dynein. Mutations in this gene can cause ciliary dyskinesia. [provided by RefSeq, Aug 2015]

DRC1 Gene-Disease associations (from GenCC):

• primary ciliary dyskinesia 21

  Inheritance: AR Classification: STRONG, MODERATE, LIMITED Submitted by: Ambry Genetics, G2P, PanelApp Australia, Labcorp Genetics (formerly Invitae)
• primary ciliary dyskinesia

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• spermatogenic failure 80

  Inheritance: AR Classification: LIMITED Submitted by: Ambry Genetics

ACMG classification

Our verdict: Likely_benign. The variant received -4 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.72).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
DRC1	NM_145038.5	c.765+6G>A		splice_region_variant, intron_variant	Intron 6 of 16	ENST00000288710.7	NP_659475.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
DRC1	ENST00000288710.7	c.765+6G>A		splice_region_variant, intron_variant	Intron 6 of 16	2	NM_145038.5	ENSP00000288710.2

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152132 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000655

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

GnomAD2 exomes AF: 0.0000119 AC: 3 AN: 251184 AF XY: 0.0000147

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000290

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000176

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000212 AC: 31 AN: 1461504 Hom.: 0 Cov.: 31 AF XY: 0.0000206 AC XY: 15 AN XY: 727048

African (AFR) AF: 0.00 AC: 0 AN: 33472

American (AMR) AF: 0.0000224 AC: 1 AN: 44700

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26118

East Asian (EAS) AF: 0.00 AC: 0 AN: 39676

South Asian (SAS) AF: 0.00 AC: 0 AN: 86226

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53382

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.0000252 AC: 28 AN: 1111784

Other (OTH) AF: 0.0000331 AC: 2 AN: 60378

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152132 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74320

African (AFR) AF: 0.0000241 AC: 1 AN: 41422

American (AMR) AF: 0.0000655 AC: 1 AN: 15270

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

East Asian (EAS) AF: 0.00 AC: 0 AN: 5194

South Asian (SAS) AF: 0.00 AC: 0 AN: 4830

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10600

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

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68026

Other (OTH) AF: 0.00 AC: 0 AN: 2090

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Primary ciliary dyskinesia Uncertain:1

Sep 01, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change falls in intron 6 of the DRC1 gene. It does not directly change the encoded amino acid sequence of the DRC1 protein. It affects a nucleotide within the consensus splice site of the intron. This variant is present in population databases (rs374715318, ExAC 0.003%). This variant has not been reported in the literature in individuals affected with DRC1-related conditions. ClinVar contains an entry for this variant (Variation ID: 407107). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant is not likely to affect RNA splicing. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.72
CADD	Benign	13
DANN	Benign	0.66
PhyloP100		0.68

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.0014
dbscSNV1_RF	Benign	0.016
SpliceAI score (max)		0.040		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: rs374715318; hg19: chr2-26653746;