chr8-38404420-G-A

Position:

• chr8-38404420-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_001286819.2(LETM2):​c.1132G>A​(p.Val378Ile) variant causes a missense change. The variant allele was found at a frequency of 0.0000031 in 1,613,488 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: LETM2 NM_001286819.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.40

Genes affected

LETM2 (HGNC:14648): (leucine zipper and EF-hand containing transmembrane protein 2) Predicted to enable ribosome binding activity. Predicted to be involved in cellular metal ion homeostasis. Predicted to be located in mitochondrial inner membrane. Predicted to be integral component of membrane. [provided by Alliance of Genome Resources, Apr 2022]

FGFR1 (HGNC:3688): (fibroblast growth factor receptor 1) The protein encoded by this gene is a member of the fibroblast growth factor receptor (FGFR) family, where amino acid sequence is highly conserved between members and throughout evolution. FGFR family members differ from one another in their ligand affinities and tissue distribution. A full-length representative protein consists of an extracellular region, composed of three immunoglobulin-like domains, a single hydrophobic membrane-spanning segment and a cytoplasmic tyrosine kinase domain. The extracellular portion of the protein interacts with fibroblast growth factors, setting in motion a cascade of downstream signals, ultimately influencing mitogenesis and differentiation. This particular family member binds both acidic and basic fibroblast growth factors and is involved in limb induction. Mutations in this gene have been associated with Pfeiffer syndrome, Jackson-Weiss syndrome, Antley-Bixler syndrome, osteoglophonic dysplasia, and autosomal dominant Kallmann syndrome 2. Chromosomal aberrations involving this gene are associated with stem cell myeloproliferative disorder and stem cell leukemia lymphoma syndrome. Alternatively spliced variants which encode different protein isoforms have been described; however, not all variants have been fully characterized. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.22882122).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
LETM2	NM_001286819.2	c.1132G>A	p.Val378Ile	missense_variant	8/11	ENST00000379957.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
LETM2	ENST00000379957.9	c.1132G>A	p.Val378Ile	missense_variant	8/11	5	NM_001286819.2	P4

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152098 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

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: 1461390 Hom.: 0 Cov.: 30 AF XY: 0.00000275 AC XY: 2 AN XY: 727064

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: 0.00000657 AC: 1 AN: 152098 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 74292

Gnomad4 AFR AF: 0.0000241

Gnomad4 AMR AF: 0.00

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

Bravo AF: 0.00000378

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Nov 02, 2023

The c.991G>A (p.V331I) alteration is located in exon 8 (coding exon 6) of the LETM2 gene. This alteration results from a G to A substitution at nucleotide position 991, causing the valine (V) at amino acid position 331 to be replaced by an isoleucine (I). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.10
BayesDel_addAF	Benign	-0.031	T
BayesDel_noAF	Benign	-0.28
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Benign	0.045	.;T;T;.;.
Eigen	Uncertain	0.40
Eigen_PC	Uncertain	0.51
FATHMM_MKL	Benign	0.35	N
LIST_S2	Uncertain	0.97	D;D;D;D;D
M_CAP	Benign	0.016	T
MetaRNN	Benign	0.23	T;T;T;T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	1.1	.;.;L;.;.
MutationTaster	Benign	1.0	D;D;D;D;D
PrimateAI	Uncertain	0.58	T
PROVEAN	Benign	-0.31	N;N;N;N;N
REVEL	Benign	0.17
Sift	Benign	0.18	T;T;T;T;T
Sift4G	Benign	0.36	T;T;T;T;T
Polyphen		0.99, 0.64	.;D;P;.;.
Vest4		0.21
MutPred		0.69		.;.;Gain of catalytic residue at L383 (P = 0.0195);.;.;
MVP		0.081
MPC		0.076
ClinPred		0.89	D
GERP RS		5.8
Varity_R		0.13
gMVP		0.32

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

Publications

LitVar

Other links and lift over

dbSNP: rs1554538746; hg19: chr8-38261938;