Evaluation of Meibomian gland dysfunction using meibography in patients with xeroderma pigmentosum.

Purpose: To assess Meibomian gland dysfunction using meibography in patients with xeroderma pigmentosum and correlate with ocular surface changes.

Methods: This cross-sectional study evaluated patients with xeroderma pigmentosum. All patients underwent a comprehensive and standardized interview.

Mutational signatures and increased retrotransposon insertions in xeroderma pigmentosum variant skin tumors.

Xeroderma pigmentosum variant (XP-V) is an autosomal recessive disease with an increased risk of developing cutaneous neoplasms in sunlight-exposed regions. These cells are deficient in the translesion synthesis (TLS) DNA polymerase eta, responsible for bypassing different types of DNA lesions. From the exome sequencing of 11 skin tumors of a genetic XP-V patients' cluster, classical mutational signatures related to sunlight exposure, such as C>T transitions targeted to pyrimidine dimers, were identified.

XPC and POLH/XPV Genes Mutated in a Genetic Cluster of Xeroderma Pigmentosum Patients in Northeast Brazil.

Xeroderma pigmentosum (XP) is a rare genetic condition in which exposure to sunlight leads to a high tumor incidence due to defective DNA repair machinery. Herein, we investigated seven patients clinically diagnosed with XP living in a small city, Montanhas (Rio Grande do Norte), in the Northeast region of Brazil. We performed high-throughput sequencing and, surprisingly, identified two different mutated genes.

Xeroderma pigmentosum variant: squamous cell carcinoma of the lower lip harboring exon 11 mutation of POLH.

Xeroderma pigmentosum (XP) is a rare inherited disease caused by deficiencies in DNA damage repair, which mainly results from the failure of nucleotide excision repair or defects in translesion DNA synthesis. The development of multiple malignancies is one of the most prominent features of this condition, which is clinically characterized by the occurrence of hyperpigmentation and lesions associated with sunlight exposure. Lip squamous cell carcinoma in patients with XP has rarely been reported, and information regarding the genetic analysis of these patients is limited.

Large deletions in immunoglobulin genes are associated with a sustained absence of DNA Polymerase η.

Somatic hypermutation of immunoglobulin genes is a highly mutagenic process that is B cell-specific and occurs during antigen-driven responses leading to antigen specificity and antibody affinity maturation. Mutations at the Ig locus are initiated by Activation-Induced cytidine Deaminase and are equally distributed at G/C and A/T bases. This requires the establishment of error-prone repair pathways involving the activity of several low fidelity DNA polymerases.

Predominant role of DNA polymerase eta and p53-dependent translesion synthesis in the survival of ultraviolet-irradiated human cells.

Genome lesions trigger biological responses that help cells manage damaged DNA, improving cell survival. Pol eta is a translesion synthesis (TLS) polymerase that bypasses lesions that block replicative polymerases, avoiding continued stalling of replication forks, which could lead to cell death. p53 also plays an important role in preventing cell death after ultraviolet (UV) light exposure.

Neonatal Paratesticular Neuroblastoma Misdiagnosed as In Utero Torsion of Testis.

Reports of neuroectodermal primary scrotal tumors are scarce. Primary paratesticular neuroblastomas seem even rarer, and only five infants with this condition have been previously described. To the authors' knowledge, this would be the first report of a neonatal congenital paratesticular neuroblastoma.

Neonatal paratesticular neuroblastoma misdiagnosed as in utero torsion of testis.

Reports of neuroectodermal primary scrotal tumors are scarce. Primary paratesticular neuroblastomas seem even rarer, and only five infants with this condition have been previously described. To the authors' knowledge, this would be the first report of a neonatal congenital paratesticular neuroblastoma.