21-42475897-C-T

Variant names:

• chr21-42475897-C-T
• NM_080860.4:c.877+1G>A

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PVS1_Strong PM2

The NM_080860.4(RSPH1):​c.877+1G>A variant causes a splice donor, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,804 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 predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 28)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: RSPH1 NM_080860.4 splice_donor, intron
• Scores: Splicing: ADA: 0.9997
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.777
• Publications: 0 publications found

Genes affected

RSPH1 (HGNC:12371): (radial spoke head component 1) This gene encodes a male meiotic metaphase chromosome-associated acidic protein. This gene is expressed in tissues with motile cilia or flagella, including the trachea, lungs, airway brushings, and testes. Mutations in this gene result in primary ciliary dyskinesia-24. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Sep 2014]

RSPH1 Gene-Disease associations (from GenCC):

• primary ciliary dyskinesia 24

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

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.16129032 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.
• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_080860.4. 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
	RSPH1	NM_080860.4	MANE Select	c.877+1G>A		splice_donor intron	N/A	NP_543136.1	Q8WYR4-1
	RSPH1	NM_001286506.2		c.763+1G>A		splice_donor intron	N/A	NP_001273435.1	Q8WYR4-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	RSPH1	ENST00000291536.8	TSL:1 MANE Select	c.877+1G>A		splice_donor intron	N/A	ENSP00000291536.3	Q8WYR4-1
	RSPH1	ENST00000856519.1		c.805+1G>A		splice_donor intron	N/A	ENSP00000526578.1
	RSPH1	ENST00000398352.3	TSL:5	c.763+1G>A		splice_donor intron	N/A	ENSP00000381395.3	Q8WYR4-2

Frequencies

GnomAD3 genomes Cov.: 28

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461804 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727212

⚠️ 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: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44718

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: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53394

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111958

Other (OTH) AF: 0.00 AC: 0 AN: 60394

⚠️ 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.: 28

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	Primary ciliary dyskinesia (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Benign	-0.11	T
BayesDel_noAF	Benign	-0.40
CADD	Pathogenic	32
DANN	Benign	0.77
Eigen	Uncertain	0.43
Eigen_PC	Benign	0.15
FATHMM_MKL	Benign	0.23	N
PhyloP100		0.78
GERP RS		2.4
Mutation Taster		=49/51	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.82
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.74		Position offset: -4
DS_DL_spliceai		0.99		Position offset: 1

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

Other links and lift over

hg19: chr21-43896007;