8-38402577-C-T

Variant names:

• chr8-38402577-C-T
• rs199861550
• NM_001286819.2:c.1037C>T

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_001286819.2(LETM2):​c.1037C>T​(p.Ala346Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,648 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A346D) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: LETM2 NM_001286819.2 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 7.57
• Publications: 3 publications found

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]

FGFR1 Gene-Disease associations (from GenCC):

• encephalocraniocutaneous lipomatosis

  Inheritance: AD Classification: DEFINITIVE Submitted by: G2P
• Hartsfield-Bixler-Demyer syndrome

  Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: G2P, Ambry Genetics, Orphanet, ClinGen
• hypogonadotropic hypogonadism 2 with or without anosmia

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
• osteoglophonic dysplasia

  Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE, LIMITED Submitted by: ClinGen, Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics, Genomics England PanelApp, Orphanet
• Pfeiffer syndrome

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
• Pfeiffer syndrome type 1

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
• Jackson-Weiss syndrome

  Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
• hypogonadotropic hypogonadism

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• isolated trigonocephaly

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Kallmann syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• septooptic dysplasia

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• tooth agenesis

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• holoprosencephaly

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

LOC102723716 (HGNC:):

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.97

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001286819.2. 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
	LETM2	NM_001286819.2	MANE Select	c.1037C>T	p.Ala346Val	missense	Exon 7 of 11	NP_001273748.1	Q2VYF4-1
	LETM2	NM_001199659.3		c.896C>T	p.Ala299Val	missense	Exon 7 of 11	NP_001186588.1	Q2VYF4-2
	LETM2	NM_001330515.2		c.893C>T	p.Ala298Val	missense	Exon 6 of 10	NP_001317444.1	E9PMA4

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	LETM2	ENST00000379957.9	TSL:5 MANE Select	c.1037C>T	p.Ala346Val	missense	Exon 7 of 11	ENSP00000369291.4	Q2VYF4-1
	LETM2	ENST00000523983.6	TSL:1	c.896C>T	p.Ala299Val	missense	Exon 7 of 11	ENSP00000428765.2	Q2VYF4-2
	LETM2	ENST00000527710.5	TSL:1	c.395C>T	p.Ala132Val	missense	Exon 4 of 8	ENSP00000434867.1	Q2VYF4-4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.0000119 AC: 3 AN: 251466 AF XY: 0.0000147

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000578

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461648 Hom.: 0 Cov.: 30 AF XY: 0.00000275 AC XY: 2 AN XY: 727144

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.0000447 AC: 2 AN: 44720

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39694

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53410

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111798

Other (OTH) AF: 0.0000166 AC: 1 AN: 60388

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ExAC AF: 0.00000824 AC: 1

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.32
BayesDel_addAF	Pathogenic	0.23	D
BayesDel_noAF	Pathogenic	0.27
CADD	Pathogenic	26
DANN	Pathogenic	1.0
DEOGEN2	Benign	0.29	T
Eigen	Pathogenic	0.96
Eigen_PC	Pathogenic	0.90
FATHMM_MKL	Benign	0.57	D
LIST_S2	Pathogenic	0.99	D
M_CAP	Uncertain	0.25	D
MetaRNN	Pathogenic	0.97	D
MetaSVM	Uncertain	0.24	D
MutationAssessor	Pathogenic	3.3	M
PhyloP100		7.6
PrimateAI	Uncertain	0.63	T
PROVEAN	Uncertain	-3.7	D
REVEL	Pathogenic	0.74
Sift	Uncertain	0.0020	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.89
MutPred		0.90		Loss of methylation at R348 (P = 0.0677)
MVP		0.39
MPC		0.36
ClinPred		0.98	D
GERP RS		5.6
Varity_R		0.66
gMVP		0.77
Mutation Taster		=21/79	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		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: rs199861550; hg19: chr8-38260095; COSMIC: COSV99907530; COSMIC: COSV99907530;