Overt and occult rheumatic diseases: the child with chronic fever

Identification of the genes involved in hereditary periodic fever syndromes has led to the recognition of a new pathophysiological category, the autoinflammatory disorders. The main non-hereditary autoinflammatory disease in childhood is systemic juvenile idiopathic arthritis (sJIA), others being the chronic infantile neurological cutaneous arthropathy (CINCA) syndrome and the periodic fever, aphthous stomatitis, pharyngitis and adenopathy (PFAPA) syndrome. Familial Mediterranean fever (FMF) has been traced to mutations in the MEFV gene. Mutations in the MVK gene, encoding the enzyme mevalonate kinase, cause the hyper-IgD periodic fever syndrome (HIDS). The tumour necrosis factor(TNF)-receptor-associated periodic syndromes (TRAPS) have been linked to mutations in theTNFRSF1A gene, encoding a TNF-alpha receptor, and the CIAS1 gene is mutated in familial cold autoinflammatory syndrome. We discuss how this knowledge has influenced diagnosis and treatment of these rare genetic disorders and how it might change our approach to the more common rheumatic diseases.

Tumor necrosis factor receptor-associated periodic syndrome (TRAPS) in a Dutch family: evidence for a TNFRSF1A mutation with reduced penetrance

Mutations of the tumor necrosis factor receptor 1 (TNFRSF1A) gene underly susceptibility to a subset of autosomal dominant recurrent fevers (ADRFs). We report on a two-generation six-member Dutch family in which a novel R92P mutation and reduced plasma TNFRSF1A levels were found in all the children, including two who are unaffected. However, only the daughter proband and father exhibited a typical TNF-receptor associated periodic syndrome (TRAPS) phenotype. PCR-RFLP analysis revealed that the mutation was not present in 120 control chromosomes from unaffected Dutch individuals. As this R92P mutation is present in two unaffected carriers it appears to be less penetrant than previously reported TNFRSF1A mutations involving cysteine residues in the extracellular domains.

Linkage of familial Hibernian fever to chromosome 12p13

Autosomal dominant periodic fevers are characterized by intermittent febrile attacks of unknown etiology and by recurrent abdominal pains. The biochemical and molecular bases of all autosomal dominant periodic fevers are unknown, and only familial Hibernian fever (FHF) has been described as a distinct clinical entity. FHF has been reported in three families-the original Irish-Scottish family and two Irish families with similar clinical features. We have undertaken a genomewide search in these families and report significant multipoint LOD scores between the disease and markers on chromosome 12p13. Cumulative multipoint linkage analyses indicate that an FHF gene is likely to be located in an 8-cM interval between D12S77 and D12S356, with a maximum LOD score (Z max) of 3.79. The two-point Z max was 3.11, for D12S77. There was no evidence of genetic heterogeneity in these three families; it is proposed that these markers should be tested in other families, of different background, that have autosomal dominant periodic fever, as a prelude to identification of the FHF-susceptibility gene.

Exclusion of the familial Mediterranean fever locus as a susceptibility region for autosomal dominant familial Hibernian fever

Autosomal dominant periodic fevers constitute a range of syndromes characterised by recurrent attacks of fever and abdominal pain. Familial Hibernian fever (FHF) has been described in only one United Kingdom based family, but two other Irish families have been found with similar clinical features. FHF resembles familial Mediterranean fever (FMF) in several clinical features, but the mode of inheritance of FHF is dominant whereas FMF is recessive. We have investigated whether autosomal dominant periodic fevers, in particular FHF, map to the FMF susceptibility locus (MEFV) on chromosome 16p13.3. We have used informative microsatellite markers flanking this locus to genotype members of the three families mentioned above. Two point and multipoint lod scores definitively excluded linkage to MEFV in the two larger families. A haplotype study confirmed these findings, indicating that FHF is genotypically as well as phenotypically distinct from FMF.

Clinical spectrum of familial Hibernian fever: a 14-year follow-up study of the index case and extended family

OBJECTIVE

To determine the clinical spectrum and natural history of the disease "familial Hibernian fever" (FHF).

DESIGN

We ascertained the disease status in all 54 living members and 9 deceased members of the extended family and conducted a detailed study of those affected.

MATERIAL AND METHODS

All family members with FHF were clinically assessed and investigated fully, including human leukocyte antigen (HLA) typing. Medical records were studied for relevant clinical features, drug therapy, and complications. All previously obtained histologic specimens were reviewed. Three typical case histories are presented.

RESULTS

The updated family tree confirmed an autosomal dominant mode of inheritance in 16 living members with FHF. In addition to the febrile attacks, abdominal pain and localized myalgias were almost invariably present. Episodic erythematous patches, conjunctivitis, and unilateral periorbital edema were also notable features. Of 10 affected male family members, 8 had inguinal hernias (in comparison with 1 of 21 unaffected male family members). No association with HLA status was noted. Secondary amyloidosis was found in one affected member.

CONCLUSION

The characteristic clinical features and natural history of FHF distinguish it from other periodic fever syndromes. The discovery of amyloidosis related to FHF alters the prognosis associated with this condition and emphasizes the need to search for effective treatment strategies. The high prevalence of inguinal herniation may provide clues about its pathogenesis.

Inheritance of renal amyloidosis in Chinese Shar-pei dogs

Renal amyloidosis (RA) and recurrent fever of unknown origin (RFUO) are characteristics of familial Mediterranean fever (FMF), a human disorder inherited as an autosomal-recessive trait. Although no animal model has been established for FMF, a similar syndrome of RFUO and RA has been reported in Chinese Shar-pei (CSP) dogs. This report addresses two questions: (1) Is RA inherited in CSP dogs? (2) If it is, is it possible to hypothesize the type of inheritance involved? Two studies were conducted to answer these questions: a historical cross-sectional comparison, which included CSP and non-CSP dogs with RA; and a prospective study that included CSP dogs with RA, RFUO, or both. The cross-sectional comparison resulted in an odds ratio of 10 for RA in CSP dogs under 7 years of age. The prospective study of 28 dogs with RA or RFUO identified 20 that had RFUO and RA, three with RA alone, and five with RFUO alone. RFUO preceded RA in all cases with both conditions. The RFUO/RA combination was observed in both sexes. Four dogs with RFUO with or without RA were born to parents that either were alive at age 7 or had died because of conditions other than kidney failure/RA. When one parent was known to express one of these conditions, the prevalence of RA was between 25% and 50% among littermates.(ABSTRACT TRUNCATED AT 250 WORDS)