Focal segmental glomerulosclerosis (FSGS) is a cause of nephrotic syndrome in children and adolescents, as well as a leading cause of kidney failure in adults. It is also known as "focal glomerular sclerosis" or "focal nodular glomerulosclerosis". It accounts for about a sixth of the cases of nephrotic syndrome. (Minimal change disease (MCD) is by far the most common cause of nephrotic syndrome in children: MCD and primary FSGS may have a similar cause.)

The individual components of the name refer to the appearance of the kidney tissue on biopsy: "focal"—only some of the glomeruli are involved (as opposed to diffuse), "segmental"—only part of each glomerulus is involved (as opposed to global), "glomerulosclerosis"—refers to scarring of the glomerulus (a part of the nephron (the functional unit of the kidney)). The glomerulosclerosis is usually indicated by heavy PAS staining and findings of immunoglobulin M (IgM) and C3-convertase (C3) in the sclerotic segment.

There is as yet inadeqaute data from randomised controlled trials.

Treatment with HAART and ACE inhibitors/Angiotensin receptor blockers has been shown to be beneficial and should be given to all patients unless otherwise contra-indicated. General renoprotective measures and the treatment of the complications of nephrotic syndrome and kidney failure are adjunctive.

Corticosteroid treatment can be useful in patients who do not respond to the above treatment. There is some evidence that ciclosporin might be helpful in selective cases, however further trials are required on both steroids and ciclosporin before these drugs can become standardised treatment if at all.

Ask-Upmark kidneys are a cause of secondary hypertension that can be curable.

Chronic allograft nephropathy, abbreviated CAN and also known as sclerosing/chronic allograft nephropathy, is the leading cause of kidney transplant failure and happens month to years after the transplant.

It is thought to be congenital or the consequence of vesicoureteral reflux.

Management of sickle nephropathy is not separate from that of overall patient management. In addition, however, the use of ACE inhibitors has been associated with improvement of the hyperfiltration glomerulopathy. Three-year graft and patient survival in kidney transplant recipients with sickle nephropathy is lower when compared to those with other causes of end-stage kidney disease.

Treatment of secondary membranous nephropathy is guided by the treatment of the original disease. For treatment of idiopathic membranous nephropathy, the treatment options include immunosuppressive drugs and non-specific anti-proteinuric measures. Recommended first line therapy often includes: cyclophosphamide alternating with a corticosteroid.

Perhaps the most difficult aspect of membranous glomerulonephritis is deciding which people to treat with immunosuppressive therapy as opposed to simple "background" or anti-proteinuric therapies. A large part of this difficulty is due to a lack of ability to predict which people will progress to end-stage renal disease, or renal disease severe enough to require dialysis. Because the above medications carry risk, treatment should not be initiated without careful consideration as to risk/benefit profile. Of note, corticosteroids (typically Prednisone) alone are of little benefit. They should be combined with one of the other 5 medications, each of which, along with prednisone, has shown some benefit in slowing down progression of membranous nephropathy. It must be kept in mind, however, that each of the 5 medications also carry their own risks, on top of prednisone.

The twin aims of treating membranous nephropathy are first to induce a remission of the nephrotic syndrome and second to prevent the development of endstage renal failure. A meta-analysis of four randomized controlled studies comparing treatments of membranous nephropathy showed that regimes comprising chlorambucil or cyclophosphamide, either alone or with steroids, were more effective than symptomatic treatment or treatment with steroids alone in inducing remission of the nephrotic syndrome.

Studies of the life expectancy of patients with Alport syndrome are rare, but one 2012 study of 456 male patients from across Europe who received a kidney transplant found that they had somewhat increased life expectancy compared to matched controls (the controls were "randomly selected from the same age, year, and modality categories").

In addition to measures for chronic kidney disease (CKD) of any cause, there is evidence that ACE inhibitors can slow the deterioration of kidney function in Alport syndrome, delaying the need for dialysis or transplantation. The development of proteinuria has been recommended as an indication for commencing treatment.

Once kidney failure has developed, patients usually do well on dialysis or with a kidney transplant. Very rarely the Alport molecule in the donor kidney causes an aggressive immune response in the recipient, 'Alport post-transplant anti-GBM disease'.

Gene therapy has been frequently discussed, but delivering it to the podocytes in the glomerulus that normally produce the type IV collagen in the glomerular basement membrane is challenging.

Diffuse proliferative nephritis (DPN) or glomerulonephritis (DPGN) is a type of glomerulonephritis that is the most serious form of renal lesions in SLE and is also the most common, occurring in 35% to 60% of patients. Most of the glomeruli show endothelial and mesangial proliferation affecting the entire glomerulus, leading to diffuse hypercellularity of the glomeruli, producing in some cases epithelial crescents that fill Bowman's space. When extensive, immune complexes create an overall thickening of the capillary wall, resembling rigid "wire loops" on routine light microscopy. Electron microscopy reveals electron-dense subendothelial immune complexes (between endothelium and basement membrane). Immune complexes can be visualized by staining with fluorescent antibodies directed against immunoglobulins or complement, resulting in a granular fluorescent staining pattern. In due course, glomerular injury gives rise to scarring (glomerulosclerosis). Most of these patients have hematuria with moderate to severe proteinuria, hypertension, and renal insufficiency.

CAN is characterized by a gradual decline in kidney function and, typically, accompanied by high blood pressure and hematuria.

Transplant glomerulopathy, abbreviated TG, is a disease of the glomeruli in transplanted kidneys. It is a type of renal injury often associated with chronic antibody-mediated rejection. However, transplant glomerulopathy is not specific for chronic antibody-mediated rejection; it may be the result of a number of disease processes affecting the glomerular endothelium.

More specifically, glomerulosclerosis can refer to:

- Focal segmental glomerulosclerosis

- Nodular glomerulosclerosis (diabetic)

Papillorenal syndrome, also called renal-coloboma syndrome or isolated renal hypoplasia, is an autosomal dominant genetic disorder marked by underdevelopment (hypoplasia) of the kidney and colobomas of the optic nerve.

Sequence analysis shows that "Pax2" is the only known gene associated with the disease. Mutations in Pax2 have been identified in half of renal coloboma syndrome victims.

HIV-associated nephropathy (HIVAN) refers to kidney disease developing in association with HIV infection. The most common, or "classical", type of HIV-associated nephropathy is a collapsing focal segmental glomerulosclerosis (FSGS), though other forms of kidney disease may also occur with HIV. Regardless of the underlying histology, renal disease in HIV-positive patients is associated with an increased risk of death.

HIVAN may be caused by direct infection of the renal cells with the HIV-1 virus, with resulting renal damage through the viral gene products. It could also be caused by changes in the release of cytokines during HIV infection. Usually occurs only in advanced disease and approximately 80% of patients with HIVAN have a CD4 count of less than 200. HIVAN presents with nephrotic syndrome and progressive kidney failure. Despite being a cause of chronic kidney failure, kidney sizes are usually normal or large.

Phakomatosis pigmentokeratotica is a rare neurocutanous condition characterized by the combination of an organoid sebaceous nevus and speckled lentiginous nevus. It is an unusual variant of epidermal naevus syndrome. It was first described by Happle "et al". It is often associated with neurological or skeletal anomalies such as hemiatrophy, dysaesthesia and hyperhidrosis in a segmental pattern, mild mental retardation, seizures, deafness, ptosis and strabismus.

Glomerulosclerosis, also known as glomerular sclerosis, refers to a hardening of the glomerulus in the kidney. It is a general term to describe scarring of the kidneys' tiny blood vessels, the glomeruli, the functional units in the kidney that filter urine from the blood.

Proteinuria (large amounts of protein in urine) is one of the signs of glomerulosclerosis. Scarring disturbs the filtering process of the kidneys and allows protein to leak from the blood into urine. However, glomerulosclerosis is one of many causes of proteinuria. A kidney biopsy (removal of tiny part of kidney with a needle) may be necessary to determine whether a patient has glomerulosclerosis or another kidney problem. About 15 percent of people with proteinuria turn out to have glomerulosclerosis.

Both children and adults can develop glomerulosclerosis and it can result from different types of kidney conditions. One frequently encountered type of glomerulosclerosis is caused by diabetes. Drug use or infections may cause focal segmental glomerulosclerosis (FSGS), a very chronic kidney condition. FSGS may also occur in patients with AIDS but most are of unknown cause.

Early stages of glomerulosclerosis may not produce any symptoms but the most important warning sign is proteinuria, usually discovered in routine medical exams. Losing large amounts of protein may cause swelling in the ankles and accumulation of fluid in the abdomen.

Scarred glomeruli cannot be repaired and many patients with glomerulosclerosis get worse over time until their kidneys fail. This condition is called end-stage renal disease (ESRD) and the patients must begin dialysis treatment or receive a kidney transplant. ESRD may be reached within a year or up to ten or more of diagnosis of glomerulosclerosis but time will vary.

Treatments for glomerulosclerosis depend on what caused the scarring of the glomeruli. This is determined by renal biopsy. Immunosuppressive drugs stop proteinuria in some patients, but once the treatments have ended proteinuria will continue. The drugs may sometimes damage the patient's kidneys even more.

Controlling the patient's blood pressure may control the progression of kidney failure. ACE inhibitors, a type of blood pressure medicine, preserve kidney function in patients with diabetes. ACE inhibitors may also slow down kidney failure for patients without diabetes. Low protein diets may also lighten the work done by kidneys to process waste. Some patients will need to control their cholesterol through diet or both diet and medicine.

The aim of the medical treatment is to slow the progression of chronic kidney disease by reducing blood pressure and albumin levels. The current published guidelines define ideal BP of <130/80 mmHg for patients with hypertensive nephropathy; studies show that anything higher or lower than this can increase cardiovascular risk. According to the African American Study of Kidney Disease (AASK) trial, after an additional 5 years follow-up upon completion of the 10-year trial, up to 65% of the cohort had progressive nephropathy despite having controlled the mean systolic BP level <135 mmHg.

ACE inhibitors, angiotensin receptor blockers, direct renin inhibitors and aldosterone antagonists, are pharmacological treatments that can be used to lower BP to target levels; hence reducing neuropathy and proteinuria progression. The management plan should be individualized based on the condition of the patients including comorbidities and previous medical history.

In addition, there are lifestyle changes that can be made. Weight reduction, exercise, reducing salt intake can be done to manage hypertensive nephropathy.

Livedoid vasculopathy (also known as "livedoid vasculitis", "livedo reticularis with summer/winter ulceration" and "segmental hyalinizing vasculitis") is a chronic cutaneous disease seen predominantly in young to middle-aged women. One synonym used to describe its features is "Painful purpuric ulcers with pattern of the lower extremities" (PURPLE).

It can be divided into a primary (or idiopathic) form and a secondary form, which has been associated with a number of diseases, including chronic venous hypertension and varicosities.

According to the United States Renal Data System (USRDS), hypertensive nephropathy accounts for more than one-third of patients on hemodialysis and the annual mortality rate for patients on hemodialysis is 23.3%.

Haemodialysis is recommended for patients who progress to end-stage kidney disease (ESKD) and hypertensive nephropathy is the second most common cause of ESKD after diabetes.

Patient prognosis is dependent on numerous factors including age, ethnicity, blood pressure and glomerular filtration rate. Changes in lifestyle factors, such as reduced salt intake and increased physical activity have been shown to improve outcomes but are insufficient without pharmacological treatment.

A contiguous gene syndrome (CGS), also known as a contiguous gene deletion syndrome is a clinical phenotype caused by a chromosomal abnormality, such as a deletion or duplication that removes several genes lying in close proximity to one another on the chromosome. The combined phenotype of the patient is a combination of what is seen when any individual has disease-causing mutations in any of the individual genes involved in the deletion. While it can be caused by deleted material on a chromosome, it is not, strictly speaking, the same entity as a segmental aneuploidy syndrome. A segmental aneuploidy syndrome is a subtype of CGS that regularly recur, usually due to non-allelic homologous recombination between low copy repeats in the region. Most CGS involve the X chromosome and affect male individuals.

One of the earliest and most famous examples of a CGS involves a male patient with Duchenne muscular dystrophy (DMD), chronic granulomatous disease (CGD), retinitis pigmentosa and intellectual disability. When it was discovered that an X chromosome deletion (specifically Xp21) was the underlying cause of all of these features, researchers were able to use this information to clone the genes responsible for DMD and CGD.

One of those more common CGS involves a deletion on the X chromosome (near Xp21) that encompasses "DMD" (causing Duchenne muscular dystrophy), "NROB1" (causing X-linked adrenal hypoplasia congenita) and "GK" (causing glycerol kinase deficiency). These patients will have all the common features of each individual disease, resulting in a very complex phenotype. Deletions near the distal tip of the p arm of the X chromosome are also a frequent cause of CGS. In addition to the previously described CGS that occur on the X chromosome, two other common syndromes are Langer-Giedion syndrome (caused by deletions of "TRPS1" and "EXT1" on 8q24 and WAGR syndrome (caused by deletions on 11q13 encompassing "PAX6" and "WT1".)

It is characterized by glomerular basement membrane thickening (referred to as "tram-tracking of the basement membrane"), increased mesangial matrix and segmental and global glomerulosclerosis.

The differential diagnosis of tram-tracking includes membranoproliferative glomerulonephritis (especially hepatitis C), and thrombotic microangiopathies.