Genetic Epilepsy
Gene: PMM2 Green List (high evidence)Green List (high evidence)
Association with HIPKD:
Cabezas et al (2017) reported co-occurrence of hyperinsulinaemic hypoglycaemia and polycystic kidney disease (HIPKD in 17 children from 11 unrelated families. Patients presented with hyperinsulinaemic hypoglycaemia in infancy and enlarged kidneys with multiple kidney cysts. Some progressed to ESKD and some had liver cysts. Whole-genome linkage analysis in 5 informative families identified a single significant locus on chromosome 16p13.2. Sequencing of the coding regions of all linked genes failed to identify biallelic mutations. Instead, they found in all patients a promoter mutation (c.-167G>T) in PMM2, either homozygous or in trans with PMM2 coding mutations. They found deglycosylation in cultured pancreatic β cells altered insulin secretion. In vitro, the PMM2 promoter mutation associated with decreased transcriptional activity in patient kidney cells and impaired binding of the transcription factor ZNF143. In silico analysis suggested an important role of ZNF143 for the formation of a chromatin loop including PMM2. They proposed that the PMM2 promoter mutation alters tissue-specific chromatin loop formation, with consequent organ-specific deficiency of PMM2 leading to the restricted phenotype of HIPKD. None of the patients exhibited the typical clinical or diagnostic features of CDG1A. Serum transferrin glycosylation was normal in 11 patients who had assessment.Created: 26 Jul 2022, 1:24 a.m. | Last Modified: 26 Jul 2022, 1:24 a.m.
Panel Version: 1.173
CDG: Well established gene-disease association.Created: 19 Jul 2021, 2:20 a.m. | Last Modified: 26 Jul 2022, 1:24 a.m.
Panel Version: 1.173
Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal
Phenotypes
Congenital disorder of glycosylation, type Ia (MIM#212065); Hyperinsulinaemic Hypoglycaemia and Polycystic Kidney Disease (HIPKD), MONDO:0020642, PMM2-related
Publications
I don't know
Encodes for phosphomannomutase 2 required for glycosylation. Not a ciliopathy gene however CDG has many overlapping features with ciliopathy. Left as Amber.
PMID: 28108845: Review article. Well reported gene causing CDG. >700 patients reported
PMID: 25497157; Many patients reported. Similar features as ciliopathies
Sources: Expert ReviewCreated: 6 May 2020, 1:19 a.m.
Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal
Phenotypes
Congenital disorder of glycosylation, type Ia (MIM#212065)
Publications
Gene: pmm2 has been classified as Green List (High Evidence).
Phenotypes for gene: PMM2 were changed from to Congenital disorder of glycosylation, type Ia (MIM#212065); Hyperinsulinaemic Hypoglycaemia and Polycystic Kidney Disease (HIPKD), MONDO:0020642, PMM2-related
Publications for gene: PMM2 were set to
Mode of inheritance for gene: PMM2 was changed from Unknown to BIALLELIC, autosomal or pseudoautosomal
gene: PMM2 was added gene: PMM2 was added to Genetic Epilepsy_AustralianGenomics_VCGS. Sources: Australian Genomics Health Alliance Epilepsy Flagship,Expert Review Green,Victorian Clinical Genetics Services Mode of inheritance for gene: PMM2 was set to Unknown
If promoting or demoting a gene, please provide comments to justify a decision to move it.
Genes included in a Genomics England gene panel for a rare disease category (green list) should fit the criteria A-E outlined below.
These guidelines were developed as a combination of the ClinGen DEFINITIVE evidence for a causal role of the gene in the disease(a), and the Developmental Disorder Genotype-Phenotype (DDG2P) CONFIRMED DD Gene evidence level(b) (please see the original references provided below for full details). These help provide a guideline for expert reviewers when assessing whether a gene should be on the green or the red list of a panel.
A. There are plausible disease-causing mutations(i) within, affecting or encompassing an interpretable functional region(ii) of this gene identified in multiple (>3) unrelated cases/families with the phenotype(iii).
OR
B. There are plausible disease-causing mutations(i) within, affecting or encompassing cis-regulatory elements convincingly affecting the expression of a single gene identified in multiple (>3) unrelated cases/families with the phenotype(iii).
OR
C. As definitions A or B but in 2 or 3 unrelated cases/families with the phenotype, with the addition of convincing bioinformatic or functional evidence of causation e.g. known inborn error of metabolism with mutation in orthologous gene which is known to have the relevant deficient enzymatic activity in other species; existence of an animal model which recapitulates the human phenotype.
AND
D. Evidence indicates that disease-causing mutations follow a Mendelian pattern of causation appropriate for reporting in a diagnostic setting(iv).
AND
E. No convincing evidence exists or has emerged that contradicts the role of the gene in the specified phenotype.
(i)Plausible disease-causing mutations: Recurrent de novo mutations convincingly affecting gene function. Rare, fully-penetrant mutations - relevant genotype never, or very rarely, seen in controls. (ii) Interpretable functional region: ORF in protein coding genes miRNA stem or loop. (iii) Phenotype: the rare disease category, as described in the eligibility statement. (iv) Intermediate penetrance genes should not be included.
It’s assumed that loss-of-function variants in this gene can cause the disease/phenotype unless an exception to this rule is known. We would like to collect information regarding exceptions. An example exception is the PCSK9 gene, where loss-of-function variants are not relevant for a hypercholesterolemia phenotype as they are associated with increased LDL-cholesterol uptake via LDLR (PMID: 25911073).
If a curated set of known-pathogenic variants is available for this gene-phenotype, please contact us at panelapp@genomicsengland.co.uk
We classify loss-of-function variants as those with the following Sequence Ontology (SO) terms:
Term descriptions can be found on the PanelApp homepage and Ensembl.
If you are submitting this evaluation on behalf of a clinical laboratory please indicate whether you report variants in this gene as part of your current diagnostic practice by checking the box
Standardised terms were used to represent the gene-disease mode of inheritance, and were mapped to commonly used terms from the different sources. Below each of the terms is described, along with the equivalent commonly-used terms.
A variant on one allele of this gene can cause the disease, and imprinting has not been implicated.
A variant on the paternally-inherited allele of this gene can cause the disease, if the alternate allele is imprinted (function muted).
A variant on the maternally-inherited allele of this gene can cause the disease, if the alternate allele is imprinted (function muted).
A variant on one allele of this gene can cause the disease. This is the default used for autosomal dominant mode of inheritance where no knowledge of the imprinting status of the gene required to cause the disease is known. Mapped to the following commonly used terms from different sources: autosomal dominant, dominant, AD, DOMINANT.
A variant on both alleles of this gene is required to cause the disease. Mapped to the following commonly used terms from different sources: autosomal recessive, recessive, AR, RECESSIVE.
The disease can be caused by a variant on one or both alleles of this gene. Mapped to the following commonly used terms from different sources: autosomal recessive or autosomal dominant, recessive or dominant, AR/AD, AD/AR, DOMINANT/RECESSIVE, RECESSIVE/DOMINANT.
A variant on one allele of this gene can cause the disease, however a variant on both alleles of this gene can result in a more severe form of the disease/phenotype.
A variant in this gene can cause the disease in males as they have one X-chromosome allele, whereas a variant on both X-chromosome alleles is required to cause the disease in females. Mapped to the following commonly used term from different sources: X-linked recessive.
A variant in this gene can cause the disease in males as they have one X-chromosome allele. A variant on one allele of this gene may also cause the disease in females, though the disease/phenotype may be less severe and may have a later-onset than is seen in males. X-linked inactivation and mosaicism in different tissues complicate whether a female presents with the disease, and can change over their lifetime. This term is the default setting used for X-linked genes, where it is not known definitately whether females require a variant on each allele of this gene in order to be affected. Mapped to the following commonly used terms from different sources: X-linked dominant, x-linked, X-LINKED, X-linked.
The gene is in the mitochondrial genome and variants within this can cause this disease, maternally inherited. Mapped to the following commonly used term from different sources: Mitochondrial.
Mapped to the following commonly used terms from different sources: Unknown, NA, information not provided.
For example, if the mode of inheritance is digenic, please indicate this in the comments and which other gene is involved.