1-228165847-A-T

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_001010867.4(IBA57):c.31A>T(p.Thr11Ser) 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. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. T11T) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 33)
• Consequence: IBA57 NM_001010867.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.271

Genes affected

IBA57 (HGNC:27302): (iron-sulfur cluster assembly factor IBA57) The protein encoded by this gene localizes to the mitochondrion and is part of the iron-sulfur cluster assembly pathway. The encoded protein functions late in the biosynthesis of mitochondrial 4Fe-4S proteins. Defects in this gene have been associated with autosomal recessive spastic paraplegia-74 and with multiple mitochondrial dysfunctions syndrome-3. Two transcript variants encoding different isoforms have been found for this gene. The smaller isoform is not likely to be localized to the mitochondrion since it lacks the amino-terminal transit peptide. [provided by RefSeq, Jul 2015]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.034189403).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
IBA57	NM_001010867.4	c.31A>T	p.Thr11Ser	missense_variant	1/3	ENST00000366711.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
IBA57	ENST00000366711.4	c.31A>T	p.Thr11Ser	missense_variant	1/3	2	NM_001010867.4	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Multiple mitochondrial dysfunctions syndrome 3;C5568837:Hereditary spastic paraplegia 74 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Dec 15, 2021

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 serine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. This variant has not been reported in the literature in individuals affected with IBA57-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces threonine, which is neutral and polar, with serine, which is neutral and polar, at codon 11 of the IBA57 protein (p.Thr11Ser). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.070
BayesDel_addAF	Benign	-0.21	T
BayesDel_noAF	Benign	-0.54
Cadd	Benign	5.0
Dann	Benign	0.69
DEOGEN2	Benign	0.00073	T
Eigen	Benign	-1.5
Eigen_PC	Benign	-1.6
FATHMM_MKL	Benign	0.0031	N
LIST_S2	Benign	0.12	T
M_CAP	Benign	0.078	D
MetaRNN	Benign	0.034	T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	0.34	N
MutationTaster	Benign	1.0	N
PrimateAI	Uncertain	0.74	T
PROVEAN	Benign	-0.040	N
REVEL	Benign	0.023
Sift	Benign	0.13	T
Sift4G	Benign	0.12	T
Polyphen		0.020	B
Vest4		0.070
MutPred		0.16		Gain of glycosylation at T11 (P = 0.0564);
MVP		0.081
MPC		0.23
ClinPred		0.14	T
GERP RS		-1.9
Varity_R		0.038
gMVP		0.34

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

Publications

LitVar

Other links and lift over

dbSNP: rs2034839816; hg19: chr1-228353548;