rs1555797038

Variant names:

• chr19-48965861-G-A
• rs1555797038
• NM_000146.4:c.194G>A

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_000146.4(FTL):​c.194G>A​(p.Arg65His) variant causes a missense 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. 15/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R65C) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: FTL NM_000146.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.02
• Publications: 0 publications found

Genes affected

FTL (HGNC:3999): (ferritin light chain) This gene encodes the light subunit of the ferritin protein. Ferritin is the major intracellular iron storage protein in prokaryotes and eukaryotes. It is composed of 24 subunits of the heavy and light ferritin chains. Variation in ferritin subunit composition may affect the rates of iron uptake and release in different tissues. A major function of ferritin is the storage of iron in a soluble and nontoxic state. Defects in this light chain ferritin gene are associated with several neurodegenerative diseases and hyperferritinemia-cataract syndrome. This gene has multiple pseudogenes. [provided by RefSeq, Jul 2008]

FTL Gene-Disease associations (from GenCC):

• hereditary hyperferritinemia with congenital cataracts

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

  Inheritance: AD Classification: STRONG, MODERATE, SUPPORTIVE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Orphanet
• L-ferritin deficiency

  Inheritance: Unknown, AD Classification: STRONG, SUPPORTIVE, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Orphanet
• genetic hyperferritinemia without iron overload

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ENSG00000305635 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.16862261).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
FTL	NM_000146.4	c.194G>A	p.Arg65His	missense_variant	Exon 2 of 4	ENST00000331825.11	NP_000137.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
FTL	ENST00000331825.11	c.194G>A	p.Arg65His	missense_variant	Exon 2 of 4	1	NM_000146.4	ENSP00000366525.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hereditary hyperferritinemia with congenital cataracts;C1853578:Neuroferritinopathy Uncertain:1

May 08, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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 output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The histidine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. ClinVar contains an entry for this variant (Variation ID: 534233). This variant has not been reported in the literature in individuals affected with FTL-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 65 of the FTL protein (p.Arg65His). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.15
BayesDel_addAF	Benign	-0.093	T
BayesDel_noAF	Benign	-0.37
CADD	Benign	18
DANN	Uncertain	0.99
DEOGEN2	Benign	0.26	T
Eigen	Benign	-0.41
Eigen_PC	Benign	-0.32
FATHMM_MKL	Uncertain	0.84	D
LIST_S2	Benign	0.77	T
M_CAP	Benign	0.013	T
MetaRNN	Benign	0.17	T
MetaSVM	Benign	-0.98	T
MutationAssessor	Benign	1.0	L
PhyloP100		1.0
PrimateAI	Benign	0.43	T
PROVEAN	Uncertain	-2.7	D
REVEL	Benign	0.065
Sift	Benign	0.15	T
Sift4G	Benign	0.12	T
Polyphen		0.0040	B
Vest4		0.12
MutPred		0.52		Loss of MoRF binding (P = 0.0234);
MVP		0.59
MPC		0.57
ClinPred		0.63	D
GERP RS		0.78
Varity_R		0.28
gMVP		0.32
Mutation Taster		=79/21	polymorphism

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: rs1555797038; hg19: chr19-49469118;