rs200334114
Variant summary
Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PM2PP3PP5_Very_Strong
The NM_001360.3(DHCR7):c.89G>C(p.Gly30Ala) variant causes a missense change. The variant allele was found at a frequency of 0.000123 in 1,614,062 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 Likely pathogenic (★★).
Frequency
Consequence
NM_001360.3 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 11 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
---|---|---|---|---|---|---|---|---|
DHCR7 | NM_001360.3 | c.89G>C | p.Gly30Ala | missense_variant | Exon 3 of 9 | ENST00000355527.8 | NP_001351.2 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000657 AC: 10AN: 152242Hom.: 0 Cov.: 33
GnomAD3 exomes AF: 0.0000636 AC: 16AN: 251494Hom.: 0 AF XY: 0.0000662 AC XY: 9AN XY: 135920
GnomAD4 exome AF: 0.000129 AC: 188AN: 1461702Hom.: 0 Cov.: 31 AF XY: 0.000129 AC XY: 94AN XY: 727182
GnomAD4 genome AF: 0.0000656 AC: 10AN: 152360Hom.: 0 Cov.: 33 AF XY: 0.0000805 AC XY: 6AN XY: 74498
ClinVar
Submissions by phenotype
Smith-Lemli-Opitz syndrome Pathogenic:6Uncertain:1
Variant summary: DHCR7 c.89G>C (p.Gly30Ala) results in a non-conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 6.4e-05 in 251594 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in DHCR7 causing Smith-Lemli-Opitz Syndrome (6.4e-05 vs 0.0043), allowing no conclusion about variant significance. c.89G>C has been reported in the literature in individuals affected with Smith-Lemli-Opitz Syndrome (Blahakova_2007, Haas_2007, Gabriel_2022). These data indicate that the variant is likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 23042628, 17497248, 17994283, 34958143). ClinVar contains an entry for this variant (Variation ID: 397518). Based on the evidence outlined above, the variant was classified as likely pathogenic. -
This heterozygous missense variant in the DHCR7 gene (autosomal recessive transmission) inherited from the mother was found to be present in combination with a second missense variant in the same gene (compound heterozygosity) in a young female patient with a severe form of ASD -
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This sequence change replaces glycine, which is neutral and non-polar, with alanine, which is neutral and non-polar, at codon 30 of the DHCR7 protein (p.Gly30Ala). This variant is present in population databases (rs200334114, gnomAD 0.01%). This missense change has been observed in individual(s) with clinical features of DHCR7-related conditions (PMID: 17497248, 17994283, 34958143). ClinVar contains an entry for this variant (Variation ID: 397518). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt DHCR7 protein function with a positive predictive value of 95%. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -
not provided Pathogenic:3Uncertain:1
DHCR7: PM3:Very Strong, PM2 -
PP3, PP4, PM2, PM3_strong -
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Not observed at a significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 28250423, 23042628, 17497248, 34958143, 34308104, 17994283, 27535533) -
Inborn genetic diseases Pathogenic:1
The c.89G>C (p.G30A) alteration is located in exon 3 (coding exon 1) of the DHCR7 gene. This alteration results from a G to C substitution at nucleotide position 89, causing the glycine (G) at amino acid position 30 to be replaced by an alanine (A). Based on data from gnomAD, the C allele has an overall frequency of 0.006% (18/282898) total alleles studied. The highest observed frequency was 0.014% (18/129194) of European (non-Finnish) alleles. This variant has been identified in conjunction with another DHCR7 variant in one individual with Smith-Lemli-Opitz confirmed by sterol analysis, in one individual with corpus callosum agenesis and ventriculomegaly, and in the fetus of one pregnant individual with increased 7-DHCR in amniotic fluid (Haas, 2007; Blahakova, 2007; Gabriel, 2022). This amino acid position is highly conserved in available vertebrate species. This alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, this alteration is classified as likely pathogenic. -
DHCR7-related disorder Pathogenic:1
The DHCR7 c.89G>C variant is predicted to result in the amino acid substitution p.Gly30Ala. This variant has been reported, along with a second causative variant, in two patients with biochemically diagnosed Smith-Lemli-Opitz syndrome (SLOS) (Haas et al. 2007. PubMed ID: 17497248). It has also been observed along with a second causative variant in a prenatal case with biochemical test results consistent with SLOS (i.e. elevated 7-dehydrocholesterol in the amniotic fluid) (Blahakova et al. 2007. PubMed ID: 17994283). In addition, the c.89G>C variant was identified, along with a nonsense variant in DHCR7 gene, in a fetus with corpus callosum agenesis, and ventriculomegaly (Table S1, Gabriel et al. 2022. PubMed ID: 34958143). This variant is reported in 0.014% of alleles in individuals of European (Non-Finnish) descent in gnomAD (http://gnomad.broadinstitute.org/variant/11-71155910-C-G). This variant is interpreted as likely pathogenic. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at