3-45827425-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP3

The NM_020347.4(LZTFL1):c.812A>G(p.Tyr271Cys) variant causes a missense change. The variant allele was found at a frequency of 0.0000062 in 1,613,858 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: 𝑓 0.000026 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000041 (1 hom.)
• Consequence: LZTFL1 NM_020347.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 3.91

Genes affected

LZTFL1 (HGNC:6741): (leucine zipper transcription factor like 1) This gene encodes a ubiquitously expressed protein that localizes to the cytoplasm. This protein interacts with Bardet-Biedl Syndrome (BBS) proteins and, through its interaction with BBS protein complexes, regulates protein trafficking to the ciliary membrane. Nonsense mutations in this gene cause a form of Bardet-Biedl Syndrome; a ciliopathy characterized in part by polydactyly, obesity, cognitive impairment, hypogonadism, and kidney failure. This gene may also function as a tumor suppressor; possibly by interacting with E-cadherin and the actin cytoskeleton and thereby regulating the transition of epithelial cells to mesenchymal cells. [provided by RefSeq, Aug 2020]

(HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.746

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
LZTFL1	NM_020347.4	c.812A>G	p.Tyr271Cys	missense_variant	9/10	ENST00000296135.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
LZTFL1	ENST00000296135.11	c.812A>G	p.Tyr271Cys	missense_variant	9/10	1	NM_020347.4	P1
	ENST00000699185.1	n.3796+25T>C		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes AF: 0.0000263 AC: 4 AN: 152230 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000654

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: 0.0000441

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000411 AC: 6 AN: 1461510 Hom.: 1 Cov.: 29 AF XY: 0.00000413 AC XY: 3 AN XY: 727066

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: 0.00000540

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000263 AC: 4 AN: 152348 Hom.: 0 Cov.: 32 AF XY: 0.0000268 AC XY: 2 AN XY: 74508

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.0000653

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000441

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000564 Hom.: 0

Bravo AF: 0.0000151

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Bardet-Biedl syndrome 17 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Jan 18, 2022

- -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Mar 24, 2022

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 (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive. ClinVar contains an entry for this variant (Variation ID: 1026239). This variant has not been reported in the literature in individuals affected with LZTFL1-related conditions. This variant is present in population databases (no rsID available, gnomAD no frequency). This sequence change replaces tyrosine, which is neutral and polar, with cysteine, which is neutral and slightly polar, at codon 271 of the LZTFL1 protein (p.Tyr271Cys). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.88
BayesDel_addAF	Pathogenic	0.23	D
BayesDel_noAF	Uncertain	0.090
Cadd	Pathogenic	26
Dann	Uncertain	1.0
DEOGEN2	Benign	0.18	T;.
Eigen	Uncertain	0.41
Eigen_PC	Uncertain	0.32
FATHMM_MKL	Uncertain	0.97	D
LIST_S2	Uncertain	0.96	D;D
M_CAP	Benign	0.045	D
MetaRNN	Pathogenic	0.75	D;D
MetaSVM	Benign	-0.96	T
MutationAssessor	Uncertain	2.4	M;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Pathogenic	0.87	D
PROVEAN	Pathogenic	-5.8	D;D
REVEL	Uncertain	0.30
Sift	Uncertain	0.0010	D;D
Sift4G	Uncertain	0.015	D;D
Polyphen		0.99	D;.
Vest4		0.83
MutPred		0.34		Loss of phosphorylation at Y271 (P = 0.0445);.;
MVP		0.46
MPC		1.6
ClinPred		1.0	D
GERP RS		1.5
Varity_R		0.66
gMVP		0.56

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs1422916311; hg19: chr3-45868917;