19-7560716-G-T

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2PP2

The NM_001166114.2(PNPLA6):​c.3768G>T​(p.Met1256Ile) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000161 in 1,613,842 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Uncertain significance in ClinVar.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000017 ( 0 hom. )

Consequence

PNPLA6
NM_001166114.2 missense

Scores

3
3
11

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 9.86

Publications

0 publications found
Variant links:
Genes affected
PNPLA6 (HGNC:16268): (patatin like phospholipase domain containing 6) This gene encodes a phospholipase that deacetylates intracellular phosphatidylcholine to produce glycerophosphocholine. It is thought to function in neurite outgrowth and process elongation during neuronal differentiation. The protein is anchored to the cytoplasmic face of the endoplasmic reticulum in both neurons and non-neuronal cells. Mutations in this gene result in autosomal recessive spastic paraplegia, and the protein is the target for neurodegeneration induced by organophosphorus compounds and chemical warfare agents. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Oct 2009]
PNPLA6 Gene-Disease associations (from GenCC):
  • ataxia-hypogonadism-choroidal dystrophy syndrome
    Inheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: G2P, Orphanet
  • PNPLA6-related spastic paraplegia with or without ataxia
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
  • retinal dystrophy-ataxia-pituitary hormone abnormality-hypogonadism syndrome
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
  • hereditary spastic paraplegia 39
    Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet
  • cerebellar ataxia-hypogonadism syndrome
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • Laurence-Moon syndrome
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • trichomegaly-retina pigmentary degeneration-dwarfism syndrome
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP2
Missense variant in the PNPLA6 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 29 curated pathogenic missense variants (we use a threshold of 10). The gene has 7 curated benign missense variants. Gene score misZ: 4.3547 (above the threshold of 3.09). Trascript score misZ: 3.5139 (above the threshold of 3.09). GenCC associations: The gene is linked to retinal dystrophy-ataxia-pituitary hormone abnormality-hypogonadism syndrome, cerebellar ataxia-hypogonadism syndrome, PNPLA6-related spastic paraplegia with or without ataxia, ataxia-hypogonadism-choroidal dystrophy syndrome, trichomegaly-retina pigmentary degeneration-dwarfism syndrome, hereditary spastic paraplegia 39, Laurence-Moon syndrome.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
PNPLA6NM_001166114.2 linkc.3768G>T p.Met1256Ile missense_variant Exon 29 of 32 ENST00000600737.6 NP_001159586.1 Q8IY17A0A384DVU0

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
PNPLA6ENST00000600737.6 linkc.3768G>T p.Met1256Ile missense_variant Exon 29 of 32 1 NM_001166114.2 ENSP00000473211.1 A0A384DVU0

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152132
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:
0.00000796
AC:
2
AN:
251298
AF XY:
0.00000736
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:
0.0000176
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000171
AC:
25
AN:
1461710
Hom.:
0
Cov.:
31
AF XY:
0.0000220
AC XY:
16
AN XY:
727168
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33476
American (AMR)
AF:
0.00
AC:
0
AN:
44718
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39698
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86250
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53406
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000216
AC:
24
AN:
1111866
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.487
Heterozygous variant carriers
0
2
4
5
7
9
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:
152132
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74306
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41410
American (AMR)
AF:
0.00
AC:
0
AN:
15274
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5188
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4826
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10622
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68024
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
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:
0.0000312
Hom.:
0

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Inborn genetic diseases Uncertain:1
May 16, 2025
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.3654G>T (p.M1218I) alteration is located in exon 32 (coding exon 30) of the PNPLA6 gene. This alteration results from a G to T substitution at nucleotide position 3654, causing the methionine (M) at amino acid position 1218 to be replaced by an isoleucine (I). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Hereditary spastic paraplegia 39 Uncertain:1
Jan 25, 2016
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

In summary, this is a novel missense change that is not predicted to affect protein function or cause disease. However, the evidence is insufficient at this time to prove that conclusively. It has been classified as a Variant of Uncertain Significance. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a PNPLA6-related disease. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated, but these predictions have not been confirmed by published functional studies. This sequence change replaces methionine with isoleucine at codon 1218 of the PNPLA6 protein (p.Met1218Ile). The methionine residue is moderately conserved and there is a small physicochemical difference between methionine and isoleucine. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.75
BayesDel_addAF
Benign
-0.084
T
BayesDel_noAF
Benign
-0.34
CADD
Uncertain
25
DANN
Uncertain
0.99
Eigen
Benign
0.0031
Eigen_PC
Benign
0.19
FATHMM_MKL
Pathogenic
1.0
D
LIST_S2
Pathogenic
0.98
.;D;D;D;D
M_CAP
Benign
0.020
T
MetaRNN
Uncertain
0.58
D;D;D;D;D
MetaSVM
Benign
-0.85
T
PhyloP100
9.9
PrimateAI
Uncertain
0.64
T
PROVEAN
Benign
-1.8
N;N;N;N;.
REVEL
Benign
0.27
Sift
Benign
0.16
T;T;T;T;.
Sift4G
Benign
0.37
T;T;T;T;T
Polyphen
0.016
B;.;.;B;.
Vest4
0.82
MVP
0.41
MPC
1.0
ClinPred
0.61
D
GERP RS
4.4
Varity_R
0.19
gMVP
0.59
Mutation Taster
=68/32
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.010
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: rs878854905; hg19: chr19-7625602; API