11-71444083-G-T

Variant names:

• chr11-71444083-G-T
• rs4316537
• NM_001360.3:c.231C>A

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP7

The NM_001360.3(DHCR7):​c.231C>A​(p.Thr77Thr) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,104 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. T77T) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: DHCR7 NM_001360.3 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -3.98
• Publications: 0 publications found

Genes affected

DHCR7 (HGNC:2860): (7-dehydrocholesterol reductase) This gene encodes an enzyme that removes the C(7-8) double bond in the B ring of sterols and catalyzes the conversion of 7-dehydrocholesterol to cholesterol. This gene is ubiquitously expressed and its transmembrane protein localizes to the endoplasmic reticulum membrane and nuclear outer membrane. Mutations in this gene cause Smith-Lemli-Opitz syndrome (SLOS); a syndrome that is metabolically characterized by reduced serum cholesterol levels and elevated serum 7-dehydrocholesterol levels and phenotypically characterized by cognitive disability, facial dysmorphism, syndactyly of second and third toes, and holoprosencephaly in severe cases to minimal physical abnormalities and near-normal intelligence in mild cases. Alternative splicing results in multiple transcript variants that encode the same protein.[provided by RefSeq, Aug 2009]

DHCR7 Gene-Disease associations (from GenCC):

• Smith-Lemli-Opitz syndrome

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), G2P, Myriad Women’s Health, ClinGen, Orphanet, Laboratory for Molecular Medicine

ACMG classification

Our verdict: Likely_benign. The variant received -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.89).
• BP7: Synonymous conserved (PhyloP=-3.98 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001360.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	DHCR7	NM_001360.3	MANE Select	c.231C>A	p.Thr77Thr	synonymous	Exon 4 of 9	NP_001351.2	A0A024R5F7
	DHCR7	NM_001425107.1		c.231C>A	p.Thr77Thr	synonymous	Exon 4 of 10	NP_001412036.1	A0A804HI25
	DHCR7	NM_001425108.1		c.231C>A	p.Thr77Thr	synonymous	Exon 4 of 9	NP_001412037.1	A0A804HJQ7

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	DHCR7	ENST00000355527.8	TSL:1 MANE Select	c.231C>A	p.Thr77Thr	synonymous	Exon 4 of 9	ENSP00000347717.4	Q9UBM7
	DHCR7	ENST00000407721.6	TSL:1	c.231C>A	p.Thr77Thr	synonymous	Exon 4 of 9	ENSP00000384739.2	Q9UBM7
	DHCR7	ENST00000685320.1		c.-333-22C>A		intron	N/A	ENSP00000509319.1	B4E1K5

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461104 Hom.: 0 Cov.: 30 AF XY: 0.00000275 AC XY: 2 AN XY: 726744

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33474

American (AMR) AF: 0.00 AC: 0 AN: 44632

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26114

East Asian (EAS) AF: 0.00 AC: 0 AN: 39670

South Asian (SAS) AF: 0.00 AC: 0 AN: 86046

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53306

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000270 AC: 3 AN: 1111722

Other (OTH) AF: 0.00 AC: 0 AN: 60372

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.89
CADD	Benign	0.12
DANN	Benign	0.77
PhyloP100		-4.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs4316537; hg19: chr11-71155129;