Xeroderma Pigmentosum: A Model for Human Premature Aging.

Aging results from intrinsic changes (chronologic) and damage from external exposures (extrinsic) on the human body. The skin is ideal to visually differentiate their unique features. Inherited diseases of DNA repair, such as xeroderma pigmentosum (XP), provide an excellent model for human aging due to the accelerated accumulation of DNA damage. Poikiloderma, atypical lentigines, and skin cancers, the primary cutaneous features of XP, occur in the general population but at a much older age. Patients with XP also exhibit ocular changes secondary to premature photoaging, including ocular surface tumors and pterygium. Internal manifestations of premature aging, including peripheral neuropathy, progressive sensorineural hearing loss, and neurodegeneration, are reported in 25% of patients with XP. Internal malignancies, such as lung cancer, CNS tumors, and leukemia and/or lymphoma, occur at a younger age in patients with XP, as do thyroid nodules. Premature ovarian failure is overrepresented among females with XP, occurring 20 years earlier than in the general population. Taken together, these clinical findings highlight the importance of DNA repair in maintaining genomic integrity. XP is a unique model of human premature aging, which is revealing new insights into aging mechanisms.

Novel Gene Deletion in NLRC4 Expanding the Familial Cold Inflammatory Syndrome Phenotype.

Familial cold inflammatory syndrome (FCAS) is a rare, inherited inflammatory disease characterized by episodes of fever, rash, and arthralgias after exposure to cold stimuli. Previous literature has established FCAS linked to autosomal dominant mutations in the NLRP3 (CIAS1) and NLRP12 genes. Moreover, there has been recent evidence of NLRC4-inflammasomopathies. Although there have been cases of FCAS secondary to missense mutations in NLRC4, we report the first symptomatic case associated with a 93-base-pair in-frame deletion within Exon 5 of the leucine rich repeat domain.

Specific Antibody Immunodeficiency Presenting With Streptococcal pneumonia-Induced Spontaneous Bacterial Peritonitis.

Specific antibody immunodeficiency (SAD) is a primary immunodeficiency disorder characterized by normal levels of serum immunoglobulins (IgG, IgA, and IgM) associated with a dysfunctional immune response. SAD is associated with recurrent infections in the setting of an insufficient response to polysaccharide vaccinations. Streptococcus pneumoniae is a well-established cause of respiratory infections in SAD. However, there has been a paucity of evidence of pneumococcal peritonitis in SAD patients, being reported as spontaneous in acquired immunodeficiency such as AIDS. We report the first case of S. pneumoniae-induced peritonitis as the presenting sign for SAD.