Genetic and Molecular Evaluation: Reporting Three Novel Mutations and Creating Awareness of Pycnodysostosis Disease.

Pycnodysostosis is a rare autosomal recessive disorder with characteristic diagnostic manifestations. This study aims to phenotype and provide molecular characterization of Egyptian patients, with emphasis on identifying unusual phenotypes and raising awareness about pycnodysostosis with different presentations to avoid a mis- or under-diagnosis and consequent mismanagement. We report on 22 Egyptian pycnodysostosis patients, including 9 new participants, all descending from consanguineous families and their ages ranging from 6 to 15 years. In addition, prenatal diagnosis was performed in one family with affected siblings. They all presented with short stature, except for one patient who presented with pancytopenia as her primary complaint. Moreover, 41.2% of patients had sleep apnea, 14% presented with craniosynostosis, and 44.4% had failure of tooth development. Molecular analysis via direct exome sequencing of the cathepsin K gene revealed three novel mutations ((NM_000396.3) c.761_763delCCT, c.864_865delAA, and c.509G>T) as well as two previously reported mutations among nine new cases. The following is our conclusion: This study expands the molecular spectrum of pycnodysostosis by identifying three novel mutations and adds to the clinical and orodental aspects of the disease. The link between the CTSK gene mutations and the failure of tooth development has not been established, and further studies could help to improve our understanding of the molecular pathology.

Is There a Link between Human Herpesvirus Infection and Toll-like Receptors in the Pathogenesis of Pityriasis Rosea? A Case-control Study.

Human herpesvirus (HHV) 6 and 7 are involved in the pathogenesis of pityriasis rosea (PR). Our aim was to evaluate the role of the innate immune response in PR through the detection of Toll-like receptors (TLR) 2, 3, 4, 7, 8, and 9 expression in the skin of affected patients and to detect the possibility of being induced by HHV-6 and/or HHV-7 viral coexistence in these patients. Twenty-four patients with PR and 24 healthy controls were included in this case-control study. Biopsy was obtained from the PR lesion and from the healthy skin of controls for detection of HHV-6 and 7 as well as TLRs 2, 3, 4, 7, 8, and 9 gene expression using real-time polymerase chain reaction (PCR). Significantly elevated expression of all studied TLRs and significantly higher viral load of HHV-6 and 7 in PR cases were detected. A significant higher expression of TLR2 and 4 in HHV-7 positive cases and a significant positive correlation between TLR9 and HHV-7 viral load were documented. HHV6 and 7 may also be involved in the pathogenesis of PR via TLR pathways.