Locus CPUM TYMS

CPUM is characterized by progressive widespread hyperpigmentation beginning at birth without accompanying symptoms. Studied children with CPUM have been born to unaffected parents. The children studied have been born with diffuse, universal, and progressive hyperpigmentation at 15 years of age. At this time the hyperpigmentation had fully progressed¹. It is not entirely clear that this is a distinct disease as it shares features with acquired universal melanosis (most similar), erythema dyschromicum perstans, lichen planus pigmentosus, and familial progressive hypigmentation.

Prevalence

Found in two monozygotic twins in Thailand¹.

Age of Onset

0 (birth)¹

HPO Terms

–

Association

Mendelian

Locus

hg19 chr18:666891-667632

hg38 chr18:666891-667632

t2t chr18:821235-821905

Details

A study has identified an intronic GATGGT hexanucleotide tandem repeat in the TYMS gene. Both parents were found to be heterozygous carriers of the expansion, suggesting a recessive inheritance pattern. Evidence is limited, only a single family with monozygotic twins have been reported and no change in expression of the gene has been observed¹.

Mechanism

LoF

Proposed mechanism involves repeat expansions in non-coding regions of the gene, reducing expression in melanocytes or keratinocytes, leading to a disruption in nucleotide balance in DNA repair and hyperpigmentation. Missense mutations disrupt nucleotide metabolism, resulting in loss-of-function and genome instability¹.

Detection

Year

2025¹

Location in Gene

Intron 3

Gene Strand

Alleles

Ref. Motif

GATGGT

Ranges

Benign (ref.)

–

Benign (gene)

–

Pathogenic (ref.)

GATGGT

Pathogenic (gene)

ACCATC

Unknown (ref.)

–

Unknown (gene)

–

Interruption (ref.)

–

Interruption (gene)

–

References

Direct supporting references for info on this page.

Intronic hexanucleotide repeat expansion in

Sunisa,Kanchanasutthiyakorn, Sakchai,Chaiyamahapurk, Siraprapa,Tongkobpetch, Kanokwan,Santawong, Chalurmpon,Srichomthong, Tippayakarn,Klomchan, Chaiyaporn,Virochsangaroon, Monnat,Pongpanich, Prateep,Warnnissorn, Sutatip,Pongcharoen, Vorasuk,Shotelersuk

Biomedical reports · 2025-06-12

pmid:40589716

Additional Literature

Additional literature related to this locus.

Raw PubMed search results
(All PubMed results returned by searching for this gene, tandem repeats, and disease, in medline format)

Genotype-phenotype correlations in breast cancer susceptibility: evaluating MMP-2, TYMS, and eNOS variants in the Jordanian population.

Mohammed,Alorjani, Laith,Al-Eitan, Haneen,Ali, Malek,Ghabbish

Scientific reports · 2026-01-08

pmid:41507280

RNA and protein immunization with

Nailma Silva Aprigio,Dos Santos, Carlos Roberto,de Almeida-Júnior, Mayra Fernanda,Ricci, Rodrigo C O,Sanches, Renata Salgado,Fernandes, Gabriela de A,Burle-Caldas, Júlia Teixeira,de Castro, João Luís,Reis-Cunha, Daniella C,Bartholomeu, Ana Clara Martins,Meira, Thaiane Gomes,Nascimento, Natalia Fernanda de Melo,Oliveira, Ricardo T,Gazzinelli, Fabiana S,Machado, Santuza M R,Teixeira

Frontiers in cellular and infection microbiology · 2025-10-17

pmid:41181325

Huntington's Disease and Huntington's Disease-like 2 (HDL2) in Martinique.

Ignacio,Antolin-Sanfeliz, Anna-Gaelle,Giguet-Valard, Sophie,Duclos, Cécile,Cazeneuve, Chloé,Angelini, Aïssatou,Signaté, Russell L,Margolis, Cyril,Goizet, Rémi,Bellance

Movement disorders clinical practice · 2025-10-11

pmid:41074680

Comparison of changes in nasal cavity and maxillary sinus volumes after facemask treatment with or without expansion in class III maxillary deficiency subjects.

Mevlude Yuce,Polat

BMC oral health · 2025-09-29

pmid:41024012

Long-read sequencing identifies ATXN3 repeat expansions, and transcriptomics reveals disease progression biomarkers and druggable targets for spinocerebellar ataxia type 3.

Chang,Liu, Xin,Wang, Chao,Xu, Xiaoxiang,Liu, Liyan,Ke, Ying,Li, Hang,Zhang, Jianqiang,Tan, Senwei,Tan, Zitong,Zhang, Liang,Cheng, Yaqiong,Ren, Lei,Shi

BMC neurology · 2025-09-01

pmid:40890629

Intronic hexanucleotide repeat expansion in

Biomedical reports · 2025-06-12

pmid:40589716

Association study of TYMS gene expression with TYMS and ENOSF1 genetic variants in neoadjuvant chemotherapy response of gastric cancer.

Khadijeh,Arjmandi, Iman,Salahshourifar, Shiva,Irani, Fereshteh,Ameli, Mohsen,Esfandbod

Journal of pathology and translational medicine · 2025-02-25

pmid:40195828

CAR-T cell expansion platforms yield distinct T cell differentiation states.

Hannah W,Song, Michaela,Prochazkova, Lipei,Shao, Roshini,Traynor, Sarah,Underwood, Mary,Black, Vicki,Fellowes, Rongye,Shi, Marie,Pouzolles, Hsien-Chao,Chou, Adam T,Cheuk, Naomi,Taylor, Ping,Jin, Robert P,Somerville, David F,Stroncek, Javed,Khan, Steven L,Highfill

Cytotherapy · 2024-03-12

pmid:38625071

Real-time

Jiejie,Guang, Shan,Wang, Bingyuan,Fan, Ziyao,Yu, Yahui,Gao, Jinru,Pan, Junting,Xi, Wei,Meng, Fang,Hu

The Analyst · 2024-03-25

pmid:38411001