20-54154024-C-T

Position:

• chr20-54154024-C-T

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_000782.5(CYP24A1):​c.*748G>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 0.000658 in 152,048 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.00066 (1 hom., cov: 33)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: CYP24A1 NM_000782.5 3_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -1.34

Genes affected

CYP24A1 (HGNC:2602): (cytochrome P450 family 24 subfamily A member 1) This gene encodes a member of the cytochrome P450 superfamily of enzymes. The cytochrome P450 proteins are monooxygenases which catalyze many reactions involved in drug metabolism and synthesis of cholesterol, steroids and other lipids. This mitochondrial protein initiates the degradation of 1,25-dihydroxyvitamin D3, the physiologically active form of vitamin D3, by hydroxylation of the side chain. In regulating the level of vitamin D3, this enzyme plays a role in calcium homeostasis and the vitamin D endocrine system. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.87).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CYP24A1	NM_000782.5	c.*748G>A		3_prime_UTR_variant	12/12	ENST00000216862.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CYP24A1	ENST00000216862.8	c.*748G>A		3_prime_UTR_variant	12/12	1	NM_000782.5	P1
CYP24A1	ENST00000395955.7	c.*748G>A		3_prime_UTR_variant	11/11	1

Frequencies

GnomAD3 genomes AF: 0.000658 AC: 100 AN: 152048 Hom.: 1 Cov.: 33

Gnomad AFR AF: 0.000145

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000262

Gnomad ASJ AF: 0.00720

Gnomad EAS AF: 0.000192

Gnomad SAS AF: 0.000416

Gnomad FIN AF: 0.000283

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.000853

Gnomad OTH AF: 0.000479

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 2 Hom.: 0 Cov.: 0 AF XY: 0.00 AC XY: 0 AN XY: 2

Gnomad4 NFE exome AF: 0.00

GnomAD4 genome AF: 0.000658 AC: 100 AN: 152048 Hom.: 1 Cov.: 33 AF XY: 0.000673 AC XY: 50 AN XY: 74272

Gnomad4 AFR AF: 0.000145

Gnomad4 AMR AF: 0.000262

Gnomad4 ASJ AF: 0.00720

Gnomad4 EAS AF: 0.000192

Gnomad4 SAS AF: 0.000416

Gnomad4 FIN AF: 0.000283

Gnomad4 NFE AF: 0.000853

Gnomad4 OTH AF: 0.000479

Alfa AF: 0.000971 Hom.: 0

Bravo AF: 0.000502

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

Hypercalcemia, infantile, 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	-0.87
CADD	Benign	0.66
DANN	Benign	0.77

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: rs371011704; hg19: chr20-52770563;