Biomedical subjects

Kanya Suphapeetiporn

Publications and source records attributed to Kanya Suphapeetiporn.

4 recordsLinked to original sources

PubMed2026

Blau syndrome initially presenting with hypercalcemia: a case report and literature review.

Blau syndrome is a rare granulomatous autoinflammatory disease typically characterized by a triad of polyarthritis, uveitis, and dermatitis. It is caused by either an inherited autosomal dominant pathogenic variant or a de novo pathogenic variant in NOD2. In this report, we present an 11-month-old boy with Blau syndrome who initially presented with calcitriol-mediated hypercalcemia. Severe hypercalcemia was controlled with intravenous fluids, diuretics, calcitonin, and a short course of corticosteroids. Following resolution of the hypercalcemic episode, the patient gradually developed the full clinical spectrum of Blau syndrome, including the classic triad, along with hepatosplenomegaly, lymphadenopathy, and bone marrow involvement. Trio genome sequencing identified a de novo heterozygous pathogenic variant in NOD2. Following the genetic diagnosis, corticosteroids and methotrexate were initiated to control the disease. This is the first reported case of Blau syndrome presenting with hypercalcemia as an initial manifestation, preceding the development of the classic triad. This case underscores the importance of considering Blau syndrome in the differential diagnosis of early-onset hypercalcemia of unknown etiology. Molecular genetic testing should be pursued in such cases to facilitate an accurate and timely diagnosis and appropriate management.

Autoinflammatory disease↗

PubMed2006

PTEN c.511C>T nonsense mutation in a BRRS family disrupts a potential exonic splicing enhancer and causes exon skipping.

Bannayan-Riley-Ruvalcaba syndrome (BRRS) is an autosomal dominant disorder characterized by macrocephaly, intestinal hamartomatous polyps, lipomas and pigmented macules of the glans penis. We identified a Thai family affected with BRRS. In addition to typical manifestations of BRRS, the proband has a large hepatic AVM which is rarely found in BRRS. The molecular analysis revealed affected members were heterozygous for an exon skipping-associated nonsense mutation c.511C>T in the PTEN gene. The mutation was previously assumed to be deleterious by causing a change to a termination codon, Q171X. We, herein, found that another pathogenic effect was splicing related by disrupting a potential exonic splicing enhancer (ESE) and causing an entire exon 6 skipping. The results prompted us to investigate other reported missense/nonsense mutations in the PTEN gene. We found that they do not colocalize with ESE sites, suggesting that most of their pathogenic effects are not through ESE disruption.

Exons↗

PubMed2004

Hypermutability in a Drosophila model for multiple endocrine neoplasia type 1.

Multiple endocrine neoplasia type I (MEN1) is an autosomal dominant cancer predisposition syndrome, the gene for which encodes a nuclear protein, menin. The biochemical function of this protein has not been completely elucidated, but several studies have shown a role in transcriptional modulation through recruitment of histone deacetylase. The mechanism by which MEN1 mutations cause tumorigenesis is unknown. The Drosophila homolog of MEN1, Mnn1, encodes a protein 50% identical to human menin. In order to further elucidate the function of MEN1, we generated a null allele of this gene in Drosophila and showed that homozygous inactivation results in morphologically normal flies that are hypersensitive to ionizing radiation and two DNA cross-linking agents, nitrogen mustard and cisplatinum. The spectrum of agents to which mutant flies are sensitive and analysis of the molecular mechanisms of this sensitivity suggest a defect in nucleotide excision repair. Drosophila Mnn1 mutants have an elevated rate of both sporadic and DNA damage-induced mutations. In a genetic background heterozygous for lats, a Drosophila and vertebrate tumor suppressor gene, homozygous inactivation of Mnn1 enhanced somatic mutation of the second allele of lats and formation of multiple primary tumors. Our data indicate that Mnn1 is a novel member of the class of autosomal dominant cancer genes that function in maintenance of genomic integrity, similar to the BRCA and HNPCC genes.

Animals↗

PubMed2002

MEN1 tumor-suppressor protein localizes to telomeres during meiosis.

Multiple endocrine neoplasia type 1 is an autosomal dominant cancer predisposition syndrome caused by mutations in the tumor-suppressor gene MEN1. The gene encodes a nuclear protein, menin, with no recognized functional motifs. Menin has been shown negatively to regulate transcriptional activation mediated by JunD, although the significance of this interaction in normal cell physiology and how the absence of menin leads to tumorigenesis are unknown. Menin is highly expressed in testes. We used immunocytochemistry to explore its role in meiosis and found that it localizes exclusively at telomeres. JunD was not found at telomeres in meiotic cells. In view of elevated telomerase activity or abnormal telomere structure in virtually all malignancies, regulation of telomere function would be an appealing role for a tumor suppressor. However, menin does not specifically associate with telomeres in somatic cells, as indicated by lack of co-localization with the known telomeric protein TRF2. Cells overexpressing menin had normal telomerase activity, and tumors with homozygous MEN1 mutations showed no aberrations in telomere length, indicating that menin does not directly regulate telomerase activity. The role of menin at meiotic telomeres appears to be independent of JunD and may not have a counterpart in somatic cells. These results suggest that menin may play different roles in different tissues through interactions with different proteins.

Genes, Tumor Suppressor↗