9-74722726-C-T

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PM2 BP4_Strong BS1_Supporting

The NM_017662.5(TRPM6):c.*1887G>A variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000854 in 152,234 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.000085 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: TRPM6 NM_017662.5 3_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.322

Genes affected

TRPM6 (HGNC:17995): (transient receptor potential cation channel subfamily M member 6) This gene is predominantly expressed in the kidney and colon, and encodes a protein containing an ion channel domain and a protein kinase domain. It is crucial for magnesium homeostasis, and plays an essential role in epithelial magnesium transport and in the active magnesium absorption in the gut and kidney. Mutations in this gene are associated with hypomagnesemia with secondary hypocalcemia. Alternatively spliced transcript variants encoding different isoforms have been noted for this gene. [provided by RefSeq, Apr 2010]

ACMG classification

Verdict is Likely_benign. Variant got -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.83).
• BS1: Variant frequency is greater than expected in population eas. gnomad4 allele frequency = 0.0000854 (13/152234) while in subpopulation EAS AF= 0.00231 (12/5186). AF 95% confidence interval is 0.00133. There are 0 homozygotes in gnomad4. There are 7 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TRPM6	NM_017662.5	c.*1887G>A		3_prime_UTR_variant	39/39	ENST00000360774.6
TRPM6	NM_001177310.2	c.*1887G>A		3_prime_UTR_variant	39/39
TRPM6	NM_001177311.2	c.*1887G>A		3_prime_UTR_variant	39/39

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TRPM6	ENST00000360774.6	c.*1887G>A		3_prime_UTR_variant	39/39	1	NM_017662.5	P4
TRPM6	ENST00000361255.7	c.*1887G>A		3_prime_UTR_variant	39/39	1		A2
TRPM6	ENST00000449912.6	c.*1887G>A		3_prime_UTR_variant	39/39	1		A2

Frequencies

GnomAD3 genomes AF: 0.0000855 AC: 13 AN: 152116 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00231

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

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 4 Hom.: 0 Cov.: 0 AF XY: 0.00 AC XY: 0 AN XY: 4

Gnomad4 NFE exome AF: 0.00

GnomAD4 genome AF: 0.0000854 AC: 13 AN: 152234 Hom.: 0 Cov.: 32 AF XY: 0.0000940 AC XY: 7 AN XY: 74438

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00231

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.0000982

Asia WGS AF: 0.000866 AC: 3 AN: 3478

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Intestinal hypomagnesemia 1 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.83
Cadd	Benign	0.99
Dann	Benign	0.46

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: rs532377785; hg19: chr9-77337642;