1-54886899-A-G

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM2PP2PP3_Moderate

The NM_014762.4(DHCR24):​c.221T>C​(p.Ile74Thr) variant causes a missense change. The variant allele was found at a frequency of 0.00000186 in 1,612,494 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

DHCR24
NM_014762.4 missense

Scores

12
6
1

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 6.78

Publications

0 publications found
Variant links:
Genes affected
DHCR24 (HGNC:2859): (24-dehydrocholesterol reductase) This gene encodes a flavin adenine dinucleotide (FAD)-dependent oxidoreductase which catalyzes the reduction of the delta-24 double bond of sterol intermediates during cholesterol biosynthesis. The protein contains a leader sequence that directs it to the endoplasmic reticulum membrane. Missense mutations in this gene have been associated with desmosterolosis. Also, reduced expression of the gene occurs in the temporal cortex of Alzheimer disease patients and overexpression has been observed in adrenal gland cancer cells. [provided by RefSeq, Jul 2008]
DHCR24-DT (HGNC:53969): (DHCR24 divergent transcript)
TMEM61 (HGNC:27296): (transmembrane protein 61) Predicted to be integral component of membrane. [provided by Alliance of Genome Resources, Apr 2022]

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP2
Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 7 curated pathogenic missense variants (we use a threshold of 10). The gene has 2 curated benign missense variants. Gene score misZ: 1.5014 (below the threshold of 3.09). Trascript score misZ: 2.3826 (below the threshold of 3.09). GenCC associations: The gene is linked to desmosterolosis.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.863

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
DHCR24NM_014762.4 linkc.221T>C p.Ile74Thr missense_variant Exon 1 of 9 ENST00000371269.9 NP_055577.1 Q15392-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
DHCR24ENST00000371269.9 linkc.221T>C p.Ile74Thr missense_variant Exon 1 of 9 1 NM_014762.4 ENSP00000360316.3 Q15392-1

Frequencies

GnomAD3 genomes
AF:
0.00000658
AC:
1
AN:
151930
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
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
AF:
0.00000137
AC:
2
AN:
1460564
Hom.:
0
Cov.:
34
AF XY:
0.00000138
AC XY:
1
AN XY:
726640
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33446
American (AMR)
AF:
0.00
AC:
0
AN:
44692
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26048
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39678
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86132
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53012
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5764
European-Non Finnish (NFE)
AF:
0.00000180
AC:
2
AN:
1111468
Other (OTH)
AF:
0.00
AC:
0
AN:
60324
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.450
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.00000658
AC:
1
AN:
151930
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74190
show subpopulations
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
41334
American (AMR)
AF:
0.00
AC:
0
AN:
15272
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5160
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4818
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10564
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
314
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
67994
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.375
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.00
Hom.:
0

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Inborn genetic diseases Uncertain:1
Jun 03, 2024
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.221T>C (p.I74T) alteration is located in exon 1 (coding exon 1) of the DHCR24 gene. This alteration results from a T to C substitution at nucleotide position 221, causing the isoleucine (I) at amino acid position 74 to be replaced by a threonine (T). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.88
BayesDel_addAF
Pathogenic
0.40
D
BayesDel_noAF
Pathogenic
0.34
CADD
Pathogenic
27
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.81
D;D;.;D
Eigen
Pathogenic
0.82
Eigen_PC
Pathogenic
0.79
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.95
.;.;D;D
M_CAP
Pathogenic
0.35
D
MetaRNN
Pathogenic
0.86
D;D;D;D
MetaSVM
Uncertain
0.72
D
MutationAssessor
Pathogenic
3.1
M;M;.;M
PhyloP100
6.8
PrimateAI
Pathogenic
0.86
D
PROVEAN
Uncertain
-3.4
.;D;.;.
REVEL
Pathogenic
0.87
Sift
Uncertain
0.0020
.;D;.;.
Sift4G
Uncertain
0.023
.;D;.;.
Polyphen
1.0
D;D;.;D
Vest4
0.76
MutPred
0.62
Gain of disorder (P = 0.0138);Gain of disorder (P = 0.0138);Gain of disorder (P = 0.0138);Gain of disorder (P = 0.0138);
MVP
0.91
MPC
2.5
ClinPred
0.99
D
GERP RS
5.3
PromoterAI
-0.048
Neutral
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.58
gMVP
0.95
Mutation Taster
=15/85
disease causing

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

Other links and lift over

dbSNP: rs1340856454; hg19: chr1-55352572; API