rs761617724

Positions:

• chr8-100213300-C-A
• chr8-100213300-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_003114.5(SPAG1):​c.1307C>A​(p.Pro436Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000462 in 1,081,660 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000046 (0 hom.)
• Consequence: SPAG1 NM_003114.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: -0.227

Genes affected

SPAG1 (HGNC:11212): (sperm associated antigen 1) The correlation of anti-sperm antibodies with cases of unexplained infertility implicates a role for these antibodies in blocking fertilization. Improved diagnosis and treatment of immunologic infertility, as well as identification of proteins for targeted contraception, are dependent on the identification and characterization of relevant sperm antigens. The protein expressed by this gene is recognized by anti-sperm agglutinating antibodies from an infertile woman. Furthermore, immunization of female rats with the recombinant human protein reduced fertility. This protein localizes to the plasma membrane of germ cells in the testis and to the post-acrosomal plasma membrane of mature spermatozoa. Recombinant polypeptide binds GTP and exhibits GTPase activity. Thus, this protein may regulate GTP signal transduction pathways involved in spermatogenesis and fertilization. Two transcript variants of this gene encode the same protein. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.07131618).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SPAG1	NM_003114.5	c.1307C>A	p.Pro436Gln	missense_variant	11/19	ENST00000388798.7	NP_003105.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SPAG1	ENST00000388798.7	c.1307C>A	p.Pro436Gln	missense_variant	11/19	1	NM_003114.5	ENSP00000373450.3
SPAG1	ENST00000251809.4	c.1307C>A	p.Pro436Gln	missense_variant	11/19	5		ENSP00000251809.3
SPAG1	ENST00000523302.1	n.214C>A		non_coding_transcript_exon_variant	1/3	3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000462 AC: 5 AN: 1081660 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 515094

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000542

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Primary ciliary dyskinesia Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Apr 20, 2017

The p.P436Q variant (also known as c.1307C>A), located in coding exon 10 of the SPAG1 gene, results from a C to A substitution at nucleotide position 1307. The proline at codon 436 is replaced by glutamine, an amino acid with similar properties. This amino acid position is not well conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Primary ciliary dyskinesia 28 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jun 24, 2021

In summary, this variant is a novel missense change that is not predicted to affect protein function. There is no indication that it causes disease, but the available evidence is currently insufficient to prove that conclusively. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated, but these predictions have not been confirmed by published functional studies. While this variant is not present in population databases, the frequency information is unreliable, as metrics indicate poor data quality at this position in the ExAC database. This variant has not been reported in the literature in an individual with a SPAG1-related disease. This sequence change replaces proline with glutamine at codon 436 of the SPAG1 protein (p.Pro436Gln). The proline residue is weakly conserved and there is a moderate physicochemical difference between proline and glutamine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.081
BayesDel_addAF	Benign	-0.21	T
BayesDel_noAF	Benign	-0.54
CADD	Benign	7.5
DANN	Benign	0.91
DEOGEN2	Benign	0.011	T;T
Eigen	Benign	-1.1
Eigen_PC	Benign	-1.2
FATHMM_MKL	Benign	0.011	N
LIST_S2	Benign	0.35	T;.
M_CAP	Benign	0.051	D
MetaRNN	Benign	0.071	T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	0.0	N;N
PrimateAI	Uncertain	0.75	T
PROVEAN	Benign	-0.56	N;N
REVEL	Benign	0.069
Sift	Benign	0.48	T;T
Sift4G	Benign	0.31	T;T
Polyphen		0.21	B;B
Vest4		0.13
MutPred		0.18		Gain of MoRF binding (P = 0.0807);Gain of MoRF binding (P = 0.0807);
MVP		0.44
MPC		0.14
ClinPred		0.058	T
GERP RS		-0.89
Varity_R		0.027
gMVP		0.24

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

LitVar

Other links and lift over

dbSNP: rs761617724; hg19: chr8-101225528;