Alport Syndrome-Like Hereditary Nephritis

Young people with genetic conditions often face challenges coping with their health condition. It can be difficult for them to meet someone with a similar condition, which is important for reinforcement of chronic illness management recommendations. Social media is used by 97% of young people in the United States and may provide those with these disorders a space for emotional expression and support. However, there is a scarcity of literature related to the use of social media among adolescents with genetic conditions as an indicator of their perception regarding their own condition.

The purpose of this pilot study was to obtain preliminary data to assess and understand social media use by young people with connective tissue disorders and determine whether they use social media to connect with patients with similar conditions or whether they would be interested in doing so.

We undertook a pilot study of selected connective tissue disorders occurring in young people between the ages of 11 and 25 years, including Marfan syndrome; Ehlers-Danlos syndrome subtypes classical, classical-like, cardiac-valvular, and vascular; Beals congenital contractual arachnodactyly; and Alport hereditary nephritis. The study took place within one pediatric clinical system. Patients were identified through electronic medical record search and International Classification of Diseases, Ninth Revision, coding at a Midwest university-based clinical system. Study subjects completed a short survey describing their experiences with their connective tissue disorders, their means of self-expression, their existing network of persons to communicate with, and their use of social media. Data analysis included nominal and bivariate regressions to compare social media use in relation to age.

Our 31 participants (42% response rate) were 55% female (17/31) and their average age was 18 years (SD 5). All participants used social media and there were no statistically significant differences between social media use and age. The majority of participants (25/30, 83%) reported that they never used social media to discuss their condition (P=.09), and only 17% (5/30) knew someone online with a similar condition (P=.50). Most participants (19/30, 63%) said they would communicate with someone with a similar disorder (P=.64).

We found that young individuals with connective tissue disorders use at least one type of social media. A majority did not use social media to discuss their condition or know someone online with a similar condition. However, many persons were interested in finding others similarly affected. Social media could serve as a platform for young people with connective tissue disorders to connect. Peer support is important in disease management and adolescent development. Future studies should aim at understanding social media use among young people with connective tissue disorders and helping them connect with other people who have similar conditions.

Alport syndrome refers to a hereditary disorder characterized by progressive renal disease and a multilaminar appearance to the glomerular basement membrane (GBM). In a small group of patients with Alport syndrome, cyclosporine A was reported to decrease proteinuria and maintain stable renal function over 7 to 10 yr of follow-up. The present study examined the effect of cyclosporine A on GBM structure and the progression to renal failure in a canine model of X-linked Alport syndrome. Affected male dogs and normal male dogs treated with cyclosporine A underwent serial renal biopsies. Body weight, serum concentrations of creatinine and albumin, and GFR were sequentially determined. Controls consisted of untreated dogs that developed end-stage renal failure by 8 mo of age. Renal biopsies were assessed for glomerulosclerosis and the percent of multilaminar GBM as measured by image analysis. Significant differences were found between treated and untreated affected dogs for weight, serum creatinine, and GFR. There was a significant delay in the progression of multilaminar change to the GBM, although treated affected dogs at termination had attained approximately 100% split GBM as did untreated affected dogs. A significant difference in the number of sclerotic glomeruli was also noted; treated dogs rarely developed obsolete glomeruli during the period studied. Interstitial fibrosis was not significantly affected by cyclosporine A treatment. These findings indicate that cyclosporine A is beneficial in slowing, but not stopping, the clinical and pathologic progression of Alport syndrome. At least part of this beneficial effect comes from a delayed deterioration of GBM structure, which in turn may be related to glomerular hemodynamics altered by cyclosporine A.

Fechtner syndrome (FTNS), also known as Alport-like syndrome, is a rare inherited condition characterized by progressive nephritis, macrothrombocytopenia, Döhle-like leukocyte inclusions, deafness, and cataract. Although it recently was shown that FTNS derives from mutation of MYH9, the gene for the heavy chain of nonmuscle myosin IIA (NMMHC-IIA), its pathophysiological characteristics remain unknown.

We studied a large FTNS family in which 10 components carried a missense mutation of MYH9 determining the D1424H substitution.

All affected subjects presented with macrothrombocytopenia and leukocyte Döhle-like bodies consisting of macroaggregates of NMMHC-IIA, but only two subjects had major renal problems characterized by proteinuria and renal failure. Electron microscopy showed focal and segmental effacement of podocytes and loss of the interpodocyte slit diaphragm. Immunohistochemistry showed apical localization of NMMHC-IIA in tubular epithelia and less podocyte staining in the two patients, whereas it was diffuse in normal epithelia. Three patients presented with stable microhematuria, and another five patients had no renal lesions, although they carried the same mutation of MYH9. Therefore, MYH9 mutation per se was responsible for platelet and leukocyte abnormalities, whereas additional predisposing conditions and/or environmental factors are necessary for nephropathy, cataract, and deafness. Looking at podocyte components conferring permselectivity properties to the kidney, we characterized the haplotype of podocin and found cosegregation of one specific allele in the two patients with nephrotic syndrome, suggesting a relationship between podocin features and proteinuria.

Our study indicates a major role for the NMMHC-IIA abnormality in the pathogenesis of leukocyte, platelet, and kidney defects in FTNS. The basic feature in all cases is aggregation and compartmentation of NMMHC-IIA. However, proteinuria and podocyte lesions are the hallmark of nephropathy in patients who develop renal failure, and podocin may have some function in this setting.