22-20982397-G-C

Variant names:

• chr22-20982397-G-C
• rs756485244
• NM_006767.4:c.26G>C

Variant summary

Our verdict is Uncertain significance. The variant received -1 ACMG points: 0P and 1B. BP4

This summary comes from the ClinGen Evidence Repository: The NM_006767.4:c.26G>C variant in LZTR1 is a missense variant predicted to cause substitution of glycine by alanine at amino acid 9 (p.Gly9Ala). The highest population minor allele frequency in gnomAD v2.1.1 is 0.0001954 (9/23990 alleles) in the South Asian population (PM2_Supporting, BS1, and BA1 are not met). The computational predictor REVEL gives a score of 0.093, which is below the threshold of 0.3, evidence that does not predict a damaging effect on LZTR1 function (BP4). In summary, this variant meets the criteria to be classified as uncertain significance for RASopathy based on the ACMG/AMP criteria applied, as specified by the ClinGen RASopathy VCEP: BP4. (ClinGen RASopathy VCEP specifications version 1.3; 12/3/2024) LINK:https://erepo.genome.network/evrepo/ui/classification/CA10118269/MONDO:0021060/094

• Frequency:
  • Genomes: 𝑓 0.000098 (1 hom., cov: 33)
  • Exomes 𝑓: 0.00011 (0 hom.)
• Consequence: LZTR1 NM_006767.4 missense
• Clinical Significance: Uncertain significance reviewed by expert panel U:7 B:1
• Conservation: PhyloP100: -0.175
• Publications: 7 publications found

Genes affected

LZTR1 (HGNC:6742): (leucine zipper like post translational regulator 1) This gene encodes a member of the BTB-kelch superfamily. Initially described as a putative transcriptional regulator based on weak homology to members of the basic leucine zipper-like family, the encoded protein subsequently has been shown to localize exclusively to the Golgi network where it may help stabilize the Gogli complex. Deletion of this gene may be associated with DiGeorge syndrome. [provided by RefSeq, Jul 2008]

LZTR1 Gene-Disease associations (from GenCC):

• LZTR1-related schwannomatosis

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
• Noonan syndrome 10

  Inheritance: AD, AR Classification: DEFINITIVE, STRONG Submitted by: G2P, PanelApp Australia, Labcorp Genetics (formerly Invitae), Ambry Genetics, Genomics England PanelApp
• schwannomatosis

  Inheritance: AD Classification: DEFINITIVE Submitted by: G2P
• Noonan syndrome

  Inheritance: AR, AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: ClinGen, Orphanet
• Noonan syndrome 2

  Inheritance: AR Classification: STRONG, MODERATE Submitted by: Ambry Genetics, PanelApp Australia, Genomics England PanelApp
• breast cancer

  Inheritance: AD Classification: MODERATE Submitted by: G2P

ENSG00000285314 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received -1 ACMG points.

• BP4: For more information check the summary or visit ClinGen Evidence Repository.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_006767.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	LZTR1	NM_006767.4	MANE Select	c.26G>C	p.Gly9Ala	missense	Exon 1 of 21	NP_006758.2

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	LZTR1	ENST00000646124.2	MANE Select	c.26G>C	p.Gly9Ala	missense	Exon 1 of 21	ENSP00000496779.1
	LZTR1	ENST00000700578.1		c.26G>C	p.Gly9Ala	missense	Exon 1 of 20	ENSP00000515073.1
	LZTR1	ENST00000645935.1		c.26G>C	p.Gly9Ala	missense	Exon 1 of 4	ENSP00000493479.1

Frequencies

GnomAD3 genomes AF: 0.0000920 AC: 14 AN: 152250 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000196

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000620

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000882

Gnomad OTH AF: 0.000478

GnomAD2 exomes AF: 0.0000979 AC: 16 AN: 163374 AF XY: 0.000148

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000823

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000942

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.000108 AC: 152 AN: 1408454 Hom.: 0 Cov.: 32 AF XY: 0.000128 AC XY: 89 AN XY: 695686

African (AFR) AF: 0.0000310 AC: 1 AN: 32304

American (AMR) AF: 0.0000542 AC: 2 AN: 36880

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25246

East Asian (EAS) AF: 0.0000271 AC: 1 AN: 36846

South Asian (SAS) AF: 0.000360 AC: 29 AN: 80504

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 48640

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5694

European-Non Finnish (NFE) AF: 0.000106 AC: 115 AN: 1084004

Other (OTH) AF: 0.0000686 AC: 4 AN: 58336

GnomAD4 genome AF: 0.0000984 AC: 15 AN: 152368 Hom.: 1 Cov.: 33 AF XY: 0.000107 AC XY: 8 AN XY: 74512

African (AFR) AF: 0.0000240 AC: 1 AN: 41590

American (AMR) AF: 0.000196 AC: 3 AN: 15314

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5184

South Asian (SAS) AF: 0.000828 AC: 4 AN: 4832

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10626

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 292

European-Non Finnish (NFE) AF: 0.0000882 AC: 6 AN: 68032

Other (OTH) AF: 0.000473 AC: 1 AN: 2114

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000982

TwinsUK AF: 0.000270 AC: 1

ALSPAC AF: 0.000519 AC: 2

ExAC AF: 0.0000602 AC: 7

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:7 Benign:1

Revision: reviewed by expert panel

Submissions by phenotype

not provided Uncertain:2

Feb 20, 2023

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge

Jan 26, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with alanine, which is neutral and non-polar, at codon 9 of the LZTR1 protein (p.Gly9Ala). This variant is present in population databases (rs756485244, gnomAD 0.04%). This variant has not been reported in the literature in individuals affected with LZTR1-related conditions. ClinVar contains an entry for this variant (Variation ID: 522164). 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 not expected to disrupt LZTR1 protein function with a negative predictive value of 95%. 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.

not specified Uncertain:1 Benign:1

May 04, 2022

Mendelics

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Mar 31, 2025

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: LZTR1 c.26G>C (p.Gly9Ala) results in a non-conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 9.8e-05 in 163374 control chromosomes. Although present at a frequency higher than estimated for Autosomal Dominant Noonan Syndrome And Related Conditions, this frequency is not significantly higher than estimated for a pathogenic variant in LZTR1 causing Autosomal Recessive Noonan Syndrome 2 (9.8e-05 vs 0.0032), allowing no conclusion about variant significance. To our knowledge, no occurrence of c.26G>C in individuals affected with Noonan Syndrome 2 and no experimental evidence demonstrating its impact on protein function have been reported. ClinVar contains an entry for this variant (Variation ID: 522164). Based on the evidence outlined above, the variant was classified as uncertain significance.

Noonan syndrome 10 Uncertain:1

Aug 10, 2022

St. Jude Molecular Pathology, St. Jude Children's Research Hospital

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The LZTR1 c.26G>C (p.Gly9Ala) missense change has a maximum subpopulation frequency of 0.038% in gnomAD v2.1.1 (https://gnomad.broadinstitute.org/). The in silico tool REVEL predicts a benign effect on protein function, but to our knowledge this prediction has not been confirmed by functional studies. To our knowledge, this variant has not been reported in individuals with Noonan syndrome or Schwannomatosis. In summary, the evidence currently available is insufficient to determine the clinical significance of this variant. It has therefore been classified as of uncertain significance.

LZTR1-related schwannomatosis Uncertain:1

Feb 11, 2024

Baylor Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Hereditary cancer-predisposing syndrome;CN230736:Cardiovascular phenotype Uncertain:1

Oct 27, 2022

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.G9A variant (also known as c.26G>C), located in coding exon 1 of the LZTR1 gene, results from a G to C substitution at nucleotide position 26. The glycine at codon 9 is replaced by alanine, an amino acid with similar properties. This amino acid position is not well conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear.

RASopathy Uncertain:1

Dec 03, 2024

ClinGen RASopathy Variant Curation Expert Panel

Significance: Uncertain significance

Review Status: reviewed by expert panel

Collection Method: curation

The NM_006767.4:c.26G>C variant in LZTR1 is a missense variant predicted to cause substitution of glycine by alanine at amino acid 9 (p.Gly9Ala). The highest population minor allele frequency in gnomAD v2.1.1 is 0.0001954 (9/23990 alleles) in the South Asian population (PM2_Supporting, BS1, and BA1 are not met). The computational predictor REVEL gives a score of 0.093, which is below the threshold of 0.3, evidence that does not predict a damaging effect on LZTR1 function (BP4). In summary, this variant meets the criteria to be classified as uncertain significance for RASopathy based on the ACMG/AMP criteria applied, as specified by the ClinGen RASopathy VCEP: BP4. (ClinGen RASopathy VCEP specifications version 1.3; 12/3/2024)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.096
BayesDel_addAF	Benign	-0.53	T
BayesDel_noAF	Benign	-0.69
CADD	Benign	13
DANN	Uncertain	0.98
DEOGEN2	Benign	0.024	T
Eigen	Benign	-0.83
Eigen_PC	Benign	-0.80
FATHMM_MKL	Benign	0.10	N
LIST_S2	Benign	0.66	T
M_CAP	Benign	0.053	D
MetaRNN	Benign	0.045	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	0.69	N
PhyloP100		-0.17
PrimateAI	Uncertain	0.60	T
PROVEAN	Benign	-0.32	N
REVEL	Benign	0.093
Sift	Benign	0.25	T
Sift4G	Benign	0.34	T
Polyphen		0.0	B
Vest4		0.084
MutPred		0.38		Gain of helix (P = 0.0496)
MVP		0.055
MPC		1.5
ClinPred		0.11	T
GERP RS		-0.98
PromoterAI		-0.0024	Neutral
RBP_binding_hub_radar		0.92
RBP_regulation_power_radar		3.1
Varity_R		0.064
gMVP		0.74
Mutation Taster		=96/4	polymorphism

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: rs756485244; hg19: chr22-21336686;