chr11-71437913-C-T
Variant summary
Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PM1PM2PP3_StrongPP5
The NM_001360.3(DHCR7):c.862G>A(p.Glu288Lys) variant causes a missense change. The variant allele was found at a frequency of 0.0000285 in 1,613,806 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 Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_001360.3 missense
Scores
Clinical Significance
Conservation
Publications
- Smith-Lemli-Opitz syndromeInheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, G2P, Myriad Women’s Health, Laboratory for Molecular Medicine, ClinGen, Labcorp Genetics (formerly Invitae)
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ACMG classification
Our verdict: Likely_pathogenic. The variant received 9 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
---|---|---|---|---|---|---|---|---|
DHCR7 | NM_001360.3 | c.862G>A | p.Glu288Lys | missense_variant | Exon 8 of 9 | ENST00000355527.8 | NP_001351.2 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000329 AC: 5AN: 152192Hom.: 0 Cov.: 34 show subpopulations
GnomAD2 exomes AF: 0.0000159 AC: 4AN: 251000 AF XY: 0.0000147 show subpopulations
GnomAD4 exome AF: 0.0000281 AC: 41AN: 1461496Hom.: 0 Cov.: 32 AF XY: 0.0000303 AC XY: 22AN XY: 727054 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000328 AC: 5AN: 152310Hom.: 0 Cov.: 34 AF XY: 0.0000269 AC XY: 2AN XY: 74468 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Smith-Lemli-Opitz syndrome Pathogenic:5Uncertain:1
Variant summary: DHCR7 c.862G>A (p.Glu288Lys) results in a conservative amino acid change located in the Transmembrane region (Peng_2018) of the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. A recent study using computational investigation to model the effect on protein and make predictions on SLOS phenotype based on structural and conservation properties reported this variant among Pathogenic alterations in the DHCR7 gene based on lower Relative solvent accesible surface area (rSASA), and higher evolutionary conservation (EC) compared with non-pathogenic variants (example, Peng_2018). This supports the notion of a critical amino acid residue essential for protein function. The variant allele was found at a frequency of 1.6e-05 in 251000 control chromosomes. c.862G>A has been reported in the literature as a compound heterozygous genotype in at-least one individual affected with Smith-Lemli-Opitz Syndrome while an earlier mutational update lists this variant among mutations in patients with Smith-Lemli-Opitz Syndrome without specifying a genotype/zygosity (example, Romano_2005, Witsch-Baumgartner_2001). 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: 29300326, 16392899, 11241839). Six clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 (LP, n=2; VUS, n=4). Based on the evidence outlined above, the variant was classified as likely pathogenic. -
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This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -
This sequence change replaces glutamic acid, which is acidic and polar, with lysine, which is basic and polar, at codon 288 of the DHCR7 protein (p.Glu288Lys). This variant is present in population databases (rs565893436, gnomAD 0.006%). This missense change has been observed in individual(s) with Smith–Lemli–Opitz syndrome (PMID: 16392899). ClinVar contains an entry for this variant (Variation ID: 500764). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae 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. -
DHCR7-related disorder Pathogenic:1
The DHCR7 c.862G>A variant is predicted to result in the amino acid substitution p.Glu288Lys. This variant has been reported in a cohort of individuals with Smith-Lemli-Opitz syndrome, though no additional information was provided on variant zygosity or patient genotype (Witsch-Baumgartner et al. 2001. PubMed ID: 11241839). It was also reported in the compound heterozygous state with a second DHCR7 variant (p.Ile251Asn) in an individual with Smith-Lemli Opitz syndrome (Romano et al. 2005. PubMed ID: 16392899). This variant is reported in 0.0058% of alleles in individuals of Latino descent in gnomAD. This variant is interpreted as likely pathogenic. -
Inborn genetic diseases Uncertain:1
The alteration results in an amino acid change:_x000D_ _x000D_ The c.862G>A (p.E288K) alteration is located in exon 8 (coding exon 6) of the DHCR7 gene. This alteration results from a G to A substitution at nucleotide position 862, causing the glutamic acid (E) at amino acid position 288 to be replaced by a lysine (K). The alteration is rare in population databases: _x000D_ _x000D_ Based on data from the Genome Aggregation Database (gnomAD), the c.862G>A alteration was observed in 0.0016% (4/25100) of total alleles studied. The alteration has been observed in affected individuals:_x000D_ _x000D_ This alteration has been described from a cohort of individuals with SLOS, as well as occurring in trans with a second missense variant in one individual with a severe phenotype (Romano, 2005; Witsch-Baumgartner, 2001). The altered amino acid is conserved throughout evolution:_x000D_ _x000D_ The p.E288 amino acid is conserved in available vertebrate species. The amino acid is located in a structurally important protein domain:_x000D_ _x000D_ The p.E288K amino acid is located in the transmembrane domain 6 (TM6) and causes changes in protein dynamics which might lead to protein dysfunction (Peng 2018). The alteration is predicted deleterious by in silico modeling:_x000D_ _x000D_ The p.E288K alteration is predicted to be deleterious by in silico analysis. Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -
not provided Uncertain:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at