4-165337848-C-A

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_006745.5(MSMO1):c.315C>A(p.His105Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000062 in 1,613,230 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: 𝑓 0.000039 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: MSMO1 NM_006745.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 1.30

Genes affected

MSMO1 (HGNC:10545): (methylsterol monooxygenase 1) Sterol-C4-mehtyl oxidase-like protein was isolated based on its similarity to the yeast ERG25 protein. It contains a set of putative metal binding motifs with similarity to that seen in a family of membrane desaturases-hydroxylases. The protein is localized to the endoplasmic reticulum membrane and is believed to function in cholesterol biosynthesis. Alternatively spliced transcript variants encoding distinct isoforms have been found for this gene. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MSMO1	NM_006745.5	c.315C>A	p.His105Gln	missense_variant	3/6	ENST00000261507.11
MSMO1	XM_005263176.3	c.315C>A	p.His105Gln	missense_variant	3/6
MSMO1	NM_001017369.3	c.-79C>A		5_prime_UTR_variant	2/5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MSMO1	ENST00000261507.11	c.315C>A	p.His105Gln	missense_variant	3/6	1	NM_006745.5	P1
MSMO1	ENST00000504317.1	c.315C>A	p.His105Gln	missense_variant	3/5	1
MSMO1	ENST00000507013.5	c.315C>A	p.His105Gln	missense_variant	3/5	2
MSMO1	ENST00000393766.6	c.-79C>A		5_prime_UTR_variant	2/5	2

Frequencies

GnomAD3 genomes AF: 0.0000394 AC: 6 AN: 152156 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000724

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000196

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: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461074 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 726902

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000360

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000394 AC: 6 AN: 152156 Hom.: 0 Cov.: 32 AF XY: 0.0000538 AC XY: 4 AN XY: 74324

Gnomad4 AFR AF: 0.0000724

Gnomad4 AMR AF: 0.000196

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000330 Hom.: 0

Bravo AF: 0.0000264

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 21, 2023

The c.315C>A (p.H105Q) alteration is located in exon 3 (coding exon 2) of the MSMO1 gene. This alteration results from a C to A substitution at nucleotide position 315, causing the histidine (H) at amino acid position 105 to be replaced by a glutamine (Q). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Dec 25, 2021

This variant is not present in population databases (gnomAD no frequency). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C15"). This variant has not been reported in the literature in individuals affected with MSMO1-related conditions. This sequence change replaces histidine, which is basic and polar, with glutamine, which is neutral and polar, at codon 105 of the MSMO1 protein (p.His105Gln). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.93
BayesDel_addAF	Pathogenic	0.20	D
BayesDel_noAF	Uncertain	0.050
Cadd	Benign	19
Dann	Uncertain	0.98
DEOGEN2	Uncertain	0.48	T;T;T
Eigen	Benign	-0.098
Eigen_PC	Benign	0.0012
FATHMM_MKL	Uncertain	0.91	D
LIST_S2	Benign	0.84	T;T;T
M_CAP	Benign	0.020	T
MetaRNN	Uncertain	0.73	D;D;D
MetaSVM	Benign	-0.96	T
MutationAssessor	Pathogenic	3.3	M;.;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.74	T
PROVEAN	Pathogenic	-6.8	D;D;D
REVEL	Uncertain	0.34
Sift	Benign	0.088	T;T;T
Sift4G	Benign	0.14	T;T;T
Polyphen		0.91	P;.;B
Vest4		0.88
MutPred		0.65		Gain of helix (P = 0.0199);Gain of helix (P = 0.0199);Gain of helix (P = 0.0199);
MVP		0.52
MPC		0.51
ClinPred		0.94	D
GERP RS		4.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.59
gMVP		0.91

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.040		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: rs1304406584; hg19: chr4-166259000;