chr16-74719083-A-G

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM1PM2PP3_ModeratePP5

The NM_024306.5(FA2H):​c.691T>C​(p.Tyr231His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000744 in 1,613,860 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000075 ( 0 hom. )

Consequence

FA2H
NM_024306.5 missense

Scores

13
5

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2U:2

Conservation

PhyloP100: 7.47

Publications

1 publications found
Variant links:
Genes affected
FA2H (HGNC:21197): (fatty acid 2-hydroxylase) This gene encodes a protein that catalyzes the synthesis of 2-hydroxysphingolipids, a subset of sphingolipids that contain 2-hydroxy fatty acids. Sphingolipids play roles in many cellular processes and their structural diversity arises from modification of the hydrophobic ceramide moiety, such as by 2-hydroxylation of the N-acyl chain, and the existence of many different head groups. Mutations in this gene have been associated with leukodystrophy dysmyelinating with spastic paraparesis with or without dystonia.[provided by RefSeq, Mar 2010]
FA2H Gene-Disease associations (from GenCC):
  • hereditary spastic paraplegia 35
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, Orphanet, Labcorp Genetics (formerly Invitae), G2P

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

PM1
In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 7 uncertain in NM_024306.5
PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.919
PP5
Variant 16-74719083-A-G is Pathogenic according to our data. Variant chr16-74719083-A-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 241464.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_024306.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
FA2H
NM_024306.5
MANE Select
c.691T>Cp.Tyr231His
missense
Exon 5 of 7NP_077282.3

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
FA2H
ENST00000219368.8
TSL:1 MANE Select
c.691T>Cp.Tyr231His
missense
Exon 5 of 7ENSP00000219368.3
FA2H
ENST00000569949.1
TSL:4
c.493T>Cp.Tyr165His
missense
Exon 5 of 5ENSP00000464576.1
FA2H
ENST00000567683.5
TSL:2
n.441T>C
non_coding_transcript_exon
Exon 3 of 5ENSP00000455126.1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152142
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000119
AC:
3
AN:
251216
AF XY:
0.0000147
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000264
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000753
AC:
11
AN:
1461718
Hom.:
0
Cov.:
33
AF XY:
0.00000963
AC XY:
7
AN XY:
727152
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86256
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53264
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000989
AC:
11
AN:
1111996
Other (OTH)
AF:
0.00
AC:
0
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.507
Heterozygous variant carriers
0
1
2
2
3
4
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152142
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74328
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41438
American (AMR)
AF:
0.00
AC:
0
AN:
15272
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5180
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10618
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68020
Other (OTH)
AF:
0.00
AC:
0
AN:
2086
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000300
Hom.:
0
Bravo
AF:
0.0000113
EpiCase
AF:
0.00
EpiControl
AF:
0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:2Uncertain:2
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Spastic paraplegia Pathogenic:1
Jun 25, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt FA2H protein function. ClinVar contains an entry for this variant (Variation ID: 241464). This missense change has been observed in individuals with clinical features of hereditary spastic paraplegia (Invitae). This variant is present in population databases (no rsID available, gnomAD 0.003%). This sequence change replaces tyrosine, which is neutral and polar, with histidine, which is basic and polar, at codon 231 of the FA2H protein (p.Tyr231His).

not provided Pathogenic:1
Apr 19, 2021
GeneDx
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Not observed at a significant frequency in large population cohorts (Lek et al., 2016); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge

not specified Uncertain:1
Sep 09, 2024
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: FA2H c.691T>C (p.Tyr231His) results in a conservative amino acid change located in the Fatty acid hydroxylase domain (IPR006694) of the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 1.2e-05 in 251216 control chromosomes (gnomAD). c.691T>C has been reported in the literature in at least one individual affected with hereditary neurodegenerative disease (Efendic_2023). These data indicate that the variant may be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication have been ascertained in the context of this evaluation (PMID: 37573804). ClinVar contains an entry for this variant (Variation ID: 241464). Based on the evidence outlined above, the variant was classified as VUS-possibly pathogenic.

Hereditary spastic paraplegia Uncertain:1
Jun 05, 2017
Genome Diagnostics Laboratory, The Hospital for Sick Children
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.98
BayesDel_addAF
Pathogenic
0.43
D
BayesDel_noAF
Pathogenic
0.45
CADD
Pathogenic
27
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.93
D
Eigen
Pathogenic
0.84
Eigen_PC
Pathogenic
0.75
FATHMM_MKL
Uncertain
0.94
D
LIST_S2
Uncertain
0.92
D
M_CAP
Pathogenic
0.46
D
MetaRNN
Pathogenic
0.92
D
MetaSVM
Pathogenic
0.95
D
MutationAssessor
Pathogenic
4.2
H
PhyloP100
7.5
PrimateAI
Uncertain
0.75
T
PROVEAN
Pathogenic
-4.7
D
REVEL
Pathogenic
0.90
Sift
Pathogenic
0.0
D
Sift4G
Uncertain
0.011
D
Polyphen
0.96
D
Vest4
0.93
MutPred
0.69
Loss of stability (P = 0.0343)
MVP
0.85
MPC
0.92
ClinPred
1.0
D
GERP RS
4.5
Varity_R
0.87
gMVP
0.96
Mutation Taster
=27/73
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

Publications

Other links and lift over

dbSNP: rs878855081; hg19: chr16-74752981; COSMIC: COSV54727897; COSMIC: COSV54727897; API