What are the other Names for this Condition? (Also known as/Synonyms)

• Autosomal Dominant Tubulointerstitial Kidney Disease-MUC1 (ADTKD-MUC1)
• MCKD1 (Medullary Cystic Kidney Disease 1)
• MUC-1 Related Autosomal Dominant Medullary Kidney Disease

What is Medullary Cystic Kidney Disease 1? (Definition/Background Information)

• Medullary Cystic Kidney Disease (MCKD) is a chronic, progressive kidney disease characterized by the presence of small renal cysts that eventually lead to end stage renal failure
• Symptoms typically appear at an average age of 28 years and may include polyuria (excessive production or passage of urine) and low urinary osmolality (decreased concentration) in the first morning urine
• Later, symptoms of renal insufficiency typically progress to include anemia, metabolic acidosis and uremia. End stage renal disease (ESRD) eventually follows
• There are 2 types of MCKD, which are both inherited in an autosomal dominant manner but are caused by mutations in different genes
• Medullary Cystic Kidney Disease 1 is caused by mutations in the MUC1 gene and MCKD 2 is caused by mutations in the UMOD gene
• The 2 types also differ by MCKD 1 being associated with ESRD at an average age of 62 years, while MCKD 2 is associated with ESRD around 32 years and is more likely to be associated with hyperuricemia and gout
• Treatment for Medullary Cystic Kidney Disease may include correction of water and electrolyte imbalances, and dialysis followed by renal transplantation for end-stage renal failure

(Source: Medullary Cystic Kidney Disease 1; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

Who gets Medullary Cystic Kidney Disease 1? (Age and Sex Distribution)

• Medullary Cystic Kidney Disease 1 is a rare, congenital disorder. The presentation of symptoms occur in adulthood, at an average age of 28 years
• Both males and females may be affected
• Worldwide, individuals of all racial and ethnic groups may be affected

What are the Risk Factors for Medullary Cystic Kidney Disease 1? (Predisposing Factors)

• A positive family history may be an important risk factor, since Medullary Cystic Kidney Disease 1 is an inherited condition
• Currently, no other risk factors have been clearly identified for MCKD 1

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Medullary Cystic Kidney Disease 1? (Etiology)

• Medullary Cystic Kidney Disease 1 may be caused by the MUC1 gene
• This gene codes for the mucoprotein-1, which is present in the distal tubules of the kidneys, gastrointestinal tract, lungs, breast and skin
• The condition is inherited in an autosomal dominant manner

Autosomal dominant inheritance: Autosomal dominant conditions are traits or disorders that are present when only one copy of the mutation is inherited on a non-sex chromosome. In these types of conditions, the individual has one normal copy and one mutant copy of the gene. The abnormal gene dominates, masking the effects of the correctly function gene. If an individual has an autosomal dominant condition, the chance of passing the abnormal gene on to their offspring is 50%. Children, who do not inherit the abnormal gene, will not develop the condition or pass it on to their offspring.

What are the Signs and Symptoms of Medullary Cystic Kidney Disease 1?

The signs and symptoms of Medullary Cystic Kidney Disease 1 may include:

• Anemia 
• Cerebral cortical atrophy 
• Decreased glomerular filtration rate 
• Elevated serum creatinine
• Glomerulosclerosis 
• Gout 
• Hypertension 
• Hypotension
• Impaired renal uric acid clearance 
• Renal cortical atrophy 
• Renal corticomedullary cysts 
• Renal hypoplasia
• Renal salt wasting 
• Stage 5 chronic kidney disease 
• Tubular atrophy 
• Tubular basement membrane disintegration 
• Tubulointerstitial fibrosis 
• Tubulointerstitial nephritis

(Source: Medullary Cystic Kidney Disease 1; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

How is Medullary Cystic Kidney Disease 1 Diagnosed?

Medullary Cystic Kidney Disease 1 is diagnosed on the basis of the following information:

• Complete physical examination
• Thorough medical history evaluation
• Assessment of signs and symptoms
• Laboratory tests
• Imaging studies
• Biopsy studies, if necessary

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Medullary Cystic Kidney Disease 1?

The complications of Medullary Cystic Kidney Disease 1 may include:

• Chronic kidney failure
• End-stage renal disease

Complications may occur with or without treatment, and in some cases, due to treatment also.

How is Medullary Cystic Kidney Disease 1 Treated?

There is no cure for Medullary Cystic Kidney Disease 1, since it is a genetic condition. The treatment is usually given to manage the signs and symptoms and any complication that develops. Treatment methods may include:

• Correction of water and electrolyte imbalances
• Dialysis for kidney failure
• Kidney transplantation for end-stage kidney disease

How can Medullary Cystic Kidney Disease 1 be Prevented?

Currently, Medullary Cystic Kidney Disease 1 may not be preventable, since it is a genetic disorder.

• Genetic testing of the expecting parents (and related family members) and prenatal diagnosis (molecular testing of the fetus during pregnancy) may help in understanding the risks better during pregnancy
• If there is a family history of the condition, then genetic counseling will help assess risks, before planning for a child
• Active research is currently being performed to explore the possibilities for treatment and prevention of inherited and acquired genetic disorders

Regular medical screening at periodic intervals with tests and physical examinations are recommended.

What is the Prognosis of Medullary Cystic Kidney Disease 1? (Outcomes/Resolutions)

• The prognosis of Medullary Cystic Kidney Disease 1 is dependent upon the severity of the signs and symptoms and associated complications, if any
• The average age at which end stage renal disease is manifested is around 64 years
• Typically, the prognosis may be assessed on a case-by-case basis

Additional and Relevant Useful Information for Medullary Cystic Kidney Disease 1:

The following DoveMed website link is a useful resource for additional information:

http://www.dovemed.com/diseases-conditions/rare-disorders/