The influence of DNA repair on neurological degeneration, cachexia, skin cancer and internal neoplasms: autopsy report of four xeroderma pigmentosum patients (XP-A, XP-C and XP-D)

Abstract

BackgroundTo investigate the association of DNA nucleotide excision repair (NER) defects with neurological degeneration, cachexia and cancer, we performed autopsies on 4 adult xeroderma pigmentosum (XP) patients with different clinical features and defects in NER complementation groups XP-A, XP-C or XP-D.ResultsThe XP-A (XP12BE) and XP-D (XP18BE) patients exhibited progressive neurological deterioration with sensorineural hearing loss. The clinical spectrum encompassed severe cachexia in the XP-A (XP12BE) patient, numerous skin cancers in the XP-A and two XP-C (XP24BE and XP1BE) patients and only few skin cancers in the XP-D patient. Two XP-C patients developed internal neoplasms including glioblastoma in XP24BE and uterine adenocarcinoma in XP1BE. At autopsy, the brains of the 44 yr XP-A and the 45 yr XP-D patients were profoundly atrophic and characterized microscopically by diffuse neuronal loss, myelin pallor and gliosis. Unlike the XP-A patient, the XP-D patient had a thickened calvarium, and the brain showed vacuolization of the neuropil in the cerebrum, cerebellum and brainstem, and patchy Purkinje cell loss. Axonal neuropathy and chronic denervation atrophy of the skeletal muscles were observed in the XP-A patient, but not in the XP-D patient.ConclusionsThese clinical manifestations and autopsy findings indicate advanced involvement of the central and peripheral nervous system. Despite similar defects in DNA repair, different clinicopathological phenotypes are seen in the four cases, and therefore distinct patterns of neurodegeneration characterize XP-D, XP-A and XP-C patients.

Other hereditary neuropathies

“…Electron microscopy of the radial nerve shows increased interstitial collagen with reduced density of large and myelinated fibers, axonal atrophy, occasional regeneration clusters, and rare thinly myelinated fibers [36].…”

Atypical Clinical Presentation of Xeroderma Pigmentosum in a Patient Harboring a Novel Missense Mutation in the <b><i>XPC</i></b> Gene: The Importance of Clinical Suspicion

“…Moreover, neurological and ophthalmological abnormalities can also be present including loss of intellectual functioning, deterioration of neurological status, impaired hearing, abnormal speech, areflexia, ataxia, peripheral neuropathy, and loss of ability to walk and talk. Pathologically this is due to a primary neuronal loss reflected as cortical atrophy and dilated ventricles [3,4]. …”

“…Early death is frequently caused by visceral metastasis from skin cancers and progressive neurodegeneration [4]. …”

Papel das proteínas XPD e DNA polimerase eta nas respostas de células humanas a danos no genoma

“…A deficiência de reparo, entretanto, está claramente associada não somente à etiologia dos tumores de pele de pacientes XP (Bradford et al, 2011;Lai et al, 2013), mas também ao desenvolvimento de sintomas oculares ) e auditivos (Totonchy et al, 2013 …”