rs530075677

Variant names:

• chr12-89523297-C-G
• NM_003774.5:c.1253G>C

Your query was ambiguous. Multiple possible variants found:

• chr12-89523297-C-G
• chr12-89523297-C-T

Variant summary

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

The NM_003774.5(GALNT4):​c.1253G>C​(p.Arg418Pro) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,700 control chromosomes in the GnomAD database, with no homozygous occurrence. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R418Q) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: GALNT4 NM_003774.5 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 2.06

Genes affected

GALNT4 (HGNC:4126): (polypeptide N-acetylgalactosaminyltransferase 4) This gene encodes a member of the UDP-N-acetyl-alpha-D-galactosamine:polypeptide N-acetylgalactosaminyltransferase (GalNAc-T) family of enzymes. GalNAc-Ts initiate mucin-type O-linked glycosylation in the Golgi apparatus by catalyzing the transfer of GalNAc to serine and threonine residues on target proteins. They are characterized by an N-terminal transmembrane domain, a stem region, a lumenal catalytic domain containing a GT1 motif and Gal/GalNAc transferase motif, and a C-terminal ricin/lectin-like domain. GalNAc-Ts have different, but overlapping, substrate specificities and patterns of expression. In vitro, the encoded protein can complement other GalNAc-Ts in the complete O-glycosylation of the mucin-1 tandem repeat and can O-glycosylate the P-selectin glycoprotein ligand-1 molecule. The coding region of this gene is contained within a single exon. Fusion transcripts, which combine part of this gene with the 5' exons of the neighboring POC1B (POC1 centriolar protein homolog B) gene, also exist. [provided by RefSeq, Dec 2010]

POC1B-GALNT4 (HGNC:42957): (POC1B-GALNT4 readthrough) This locus represents naturally occurring transcripts that splice the 5' exons of the POC1B (POC1 centriolar protein homolog B) gene on chromosome 12 to the GALNT4 (UDP-N-acetyl-alpha-D-galactosamine:polypeptide N-acetylgalactosaminyltransferase 4) gene, which is located within a POC1B intron. Alternative splicing results in two transcript variants, one of which encodes a fusion isoform that shares sequence identity with the products of each individual gene. [provided by RefSeq, Dec 2010]

POC1B (HGNC:30836): (POC1 centriolar protein B) POC1 proteins contain an N-terminal WD40 domain and a C-terminal coiled coil domain and are part of centrosomes. They play an important role in basal body and cilia formation. This gene encodes one of the two POC1 proteins found in humans. Mutation in this gene result in autosomal-recessive cone-rod dystrophy. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Oct 2014]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GALNT4	NM_003774.5	c.1253G>C	p.Arg418Pro	missense_variant	Exon 1 of 1	ENST00000529983.3	NP_003765.2
POC1B	NM_172240.3	c.100+1823G>C		intron_variant	Intron 2 of 11	ENST00000313546.8	NP_758440.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GALNT4	ENST00000529983.3	c.1253G>C	p.Arg418Pro	missense_variant	Exon 1 of 1	6	NM_003774.5	ENSP00000436604.2
POC1B-GALNT4	ENST00000548729.5	c.1244G>C	p.Arg415Pro	missense_variant	Exon 3 of 3	2		ENSP00000447852.1
POC1B	ENST00000313546.8	c.100+1823G>C		intron_variant	Intron 2 of 11	1	NM_172240.3	ENSP00000323302.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461700 Hom.: 0 Cov.: 85 AF XY: 0.00000275 AC XY: 2 AN XY: 727128

Gnomad4 AFR exome AF: 0.0000299

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: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.87
BayesDel_addAF	Uncertain	0.040	T
BayesDel_noAF	Benign	-0.18
CADD	Benign	21
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.59	D;.
Eigen	Uncertain	0.31
Eigen_PC	Benign	0.21
FATHMM_MKL	Uncertain	0.84	D
LIST_S2	Uncertain	0.97	D;D
M_CAP	Benign	0.042	D
MetaRNN	Uncertain	0.57	D;D
MetaSVM	Benign	-0.47	T
MutationAssessor	Pathogenic	3.1	M;.
PrimateAI	Uncertain	0.53	T
PROVEAN	Uncertain	-4.0	D;D
REVEL	Benign	0.24
Sift	Uncertain	0.0080	D;D
Sift4G	Uncertain	0.045	D;T
Polyphen		0.60	P;P
Vest4		0.56
MutPred		0.60		Loss of MoRF binding (P = 0.0064);.;
MVP		0.52
MPC		0.46
ClinPred		0.96	D
GERP RS		5.0
Varity_R		0.86
gMVP		0.93

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

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

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr12-89917074;