21-46222695-G-C

Variant names:

• chr21-46222695-G-C
• NM_002340.6:c.363C>G
• LSS p.Ala121Ala

Variant summary

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

The NM_002340.6(LSS):​c.363C>G​(p.Ala121Ala) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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. A121A) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 34)
• Consequence: LSS NM_002340.6 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -4.17
• Publications: 0 publications found

Genes affected

LSS (HGNC:6708): (lanosterol synthase) The protein encoded by this gene catalyzes the conversion of (S)-2,3 oxidosqualene to lanosterol. The encoded protein is a member of the terpene cyclase/mutase family and catalyzes the first step in the biosynthesis of cholesterol, steroid hormones, and vitamin D. Alternative splicing results in multiple transcript variants encoding different isoforms.[provided by RefSeq, Feb 2009]

LSS Gene-Disease associations (from GenCC):

• alopecia-intellectual disability syndrome 4

  Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• cataract 44

  Inheritance: AR Classification: STRONG, LIMITED Submitted by: G2P, Labcorp Genetics (formerly Invitae), Ambry Genetics
• hypotrichosis 14

  Inheritance: AR Classification: MODERATE Submitted by: Ambry Genetics
• hypotrichosis simplex

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• total early-onset cataract

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• autosomal recessive palmoplantar keratoderma and congenital alopecia

  Inheritance: AR Classification: LIMITED Submitted by: G2P

ENSG00000223901 (HGNC:):

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=-0.81).
• BP7: Synonymous conserved (PhyloP=-4.18 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_002340.6. 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
	LSS	NM_002340.6	MANE Select	c.363C>G	p.Ala121Ala	synonymous	Exon 4 of 22	NP_002331.3
	LSS	NM_001001438.3		c.363C>G	p.Ala121Ala	synonymous	Exon 4 of 23	NP_001001438.1	P48449-1
	LSS	NM_001145436.2		c.363C>G	p.Ala121Ala	synonymous	Exon 4 of 22	NP_001138908.1	P48449-3

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	LSS	ENST00000397728.8	TSL:1 MANE Select	c.363C>G	p.Ala121Ala	synonymous	Exon 4 of 22	ENSP00000380837.2	P48449-1
	LSS	ENST00000356396.8	TSL:1	c.363C>G	p.Ala121Ala	synonymous	Exon 4 of 23	ENSP00000348762.3	P48449-1
	LSS	ENST00000457828.6	TSL:1	c.123C>G	p.Ala41Ala	synonymous	Exon 3 of 21	ENSP00000409191.2	P48449-2

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 34

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.81
CADD	Benign	0.098
DANN	Benign	0.80
PhyloP100		-4.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.050		Details are displayed if max score is > 0.2

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

hg19: chr21-47642609;