1-240092656-A-T

Variant names:

• chr1-240092656-A-T
• rs757511770
• NM_020066.5:c.547A>T

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 10P and 1B. PM2 PP5_Very_Strong BP4

The NM_020066.5(FMN2):​c.547A>T​(p.Ile183Phe) 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. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: FMN2 NM_020066.5 missense
• Clinical Significance: Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 3.26
• Publications: 1 publications found

Genes affected

FMN2 (HGNC:14074): (formin 2) This gene is a member of the formin homology protein family. The encoded protein is thought to have essential roles in organization of the actin cytoskeleton and in cell polarity. This protein mediates the formation of an actin mesh that positions the spindle during oogenesis and also regulates the formation of actin filaments in the nucleus. This protein also forms a perinuclear actin/focal-adhesion system that regulates the shape and position of the nucleus during cell migration. Mutations in this gene have been associated with infertility and also with an autosomal recessive form of intellectual disability (MRT47). Alternatively spliced transcript variants have been identified. [provided by RefSeq, Jul 2017]

FMN2 Gene-Disease associations (from GenCC):

• intellectual disability, autosomal recessive 47

  Inheritance: AR Classification: STRONG Submitted by: Ambry Genetics, G2P, Labcorp Genetics (formerly Invitae)
• autosomal recessive non-syndromic intellectual disability

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_pathogenic. The variant received 9 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 1-240092656-A-T is Pathogenic according to our data. Variant chr1-240092656-A-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 429780.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BP4: Computational evidence support a benign effect (MetaRNN=0.18868265). . Strength limited to SUPPORTING due to the PP5.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
FMN2	NM_020066.5	c.547A>T	p.Ile183Phe	missense_variant	Exon 1 of 18	ENST00000319653.14	NP_064450.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
FMN2	ENST00000319653.14	c.547A>T	p.Ile183Phe	missense_variant	Exon 1 of 18	5	NM_020066.5	ENSP00000318884.9
FMN2	ENST00000447095.5	c.-87+24583A>T		intron_variant	Intron 2 of 6	3		ENSP00000409308.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 89

GnomAD4 genome Cov.: 33

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:1

Nov 13, 2015

GeneDx

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The I183F variant in the FMN2 gene has not been reported previously as a pathogenic variant, nor as a benign variant, to our knowledge. The I183F variant was not observed in approximately 6500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. The I183F variant is a conservative amino acid substitution, which is not likely to impact secondary protein structure as these residues share similar properties. This substitution occurs at a position where amino acids with similar properties to Isoleucine are tolerated across species. In silico analysis is inconsistent in its predictions as to whether or not the variant is damaging to the protein structure/function. The I183F variant is a strong candidate for a pathogenic variant, however the possibility it may be a rare benign variant cannot be excluded. -

Intellectual disability, autosomal recessive 47 Pathogenic:1

Feb 23, 2018

Geisinger Autism and Developmental Medicine Institute, Geisinger Health System

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing;provider interpretation

This variant was identified in an 11 year old female with autism spectrum disorder, global developmental delay, microcephaly, coordination disorder, a single seizure, imperforate anus, intermittent exotropia, and history of hydronephrosis. Initial EEG at age 3 was normal; EEG at age 4 following a single unprovoked seizure showed biposterior slowing. The variant is absent from the gnomAD database, and it was found to be de novo (with maternity and paternity confirmed). Computational prediction models are inconsistent. A second variant in FMN2 was not identified. Additionally, whole exome sequencing also identified another variant of uncertain significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.91
BayesDel_addAF	Benign	-0.077	T
BayesDel_noAF	Benign	-0.35
CADD	Uncertain	23
DANN	Benign	0.91
DEOGEN2	Benign	0.23	T
Eigen	Benign	-0.035
Eigen_PC	Benign	-0.023
FATHMM_MKL	Uncertain	0.77	D
LIST_S2	Benign	0.81	T
M_CAP	Uncertain	0.097	D
MetaRNN	Benign	0.19	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	1.7	L
PhyloP100		3.3
PrimateAI	Pathogenic	0.92	D
PROVEAN	Uncertain	-2.6	D
REVEL	Benign	0.15
Sift	Uncertain	0.0020	D
Sift4G	Uncertain	0.0060	D
Polyphen		0.72	P
Vest4		0.25
MutPred		0.059		Gain of phosphorylation at S185 (P = 0.235);
MVP		0.45
MPC		1.2
ClinPred		0.93	D
GERP RS		2.5
Varity_R		0.40
gMVP		0.32
Mutation Taster		=85/15	disease causing (ClinVar)

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: rs757511770; hg19: chr1-240255956;