Paediatric pseudo-obstruction syndrome

Gene: TYMP

Green List (high evidence)

The rating of this gene has been updated to Green and the mode of inheritance set to 'BIALLELIC, autosomal or pseudoautosomal' following NHS Genomic Medicine Service approval.

Created: 1 Feb 2023, 7:44 a.m. | Last Modified: 1 Feb 2023, 7:44 a.m.

Panel Version: 0.216

Comment on list classification: This gene should be rated GREEN as this gene has been associated with mitochondrial DNA depletion syndrome 1 (MNGIE type) (MIM #603041) from multiple unrelated cases from several different studies.

This disorder is characterised by ptosis, progressive external ophthalmoplegia (PEO), gastrointestinal dysmotility (often pseudoobstruction), cachexia, diffuse leukoencephalopathy, peripheral neuropathy, and mitochondrial dysfunction.

A recent study in PMID:33825174 reports five novel variants from TYMP gene in six Iranian patients for whom the onset of symptoms varied between 13 to 20 years of age.

This gene has been associated with phenotypes in OMIM, but not in G2P.

Created: 2 Jan 2023, 9:49 p.m. | Last Modified: 2 Jan 2023, 9:49 p.m.

Panel Version: 0.163

Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal

Phenotypes
Mitochondrial DNA depletion syndrome 1 (MNGIE type), OMIM:603041

Publications

• 31848803
• 32898308
• 33825174

Review submitted on behalf of Dr. Anna Rybak and Dr. Osvaldo Borreli, Great Ormond Street Hospital for Children NHS Foundation Trust. Gene group: Mitochondrial depletion disorders (MNGIE, MELAS, myopathy, other). Protein function: encodes thymidine phosphorylase.

Created: 20 Dec 2022, 3:32 p.m. | Last Modified: 20 Dec 2022, 3:32 p.m.

Panel Version: 0.2

Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal

Phenotypes
Accumulation of thymidine in mitochondrial DNA leads to impaired function. Multi-system mitochondrial disease with progressive gastrointestinal dysmotility

Publications

• 31848803