PKD or Polycystic Kidney Disease
Polycystic Kidney Disease is a range of genetic disorders that cause renal (kidney) failure, damage to other organs and sometimes result in premature death in children and adults. There are two major forms of PKD:
- ADPKD - AUTOSOMAL DOMINANT POLYCYSTIC KIDNEY DISEASE
- ARPKD - AUTOSOMAL RECESSIVE POLYCYSTIC KIDNEY DISEASE
Genetic disorders like PKD happen when abnormalities or mutations occur in single genes inside human cells. Genes contain DNA, the 'building blocks' of life which contain instructions for making the proteins that are necessary for human development. When there is a genetic mutation, the proteins don't work properly or are sometimes missed. In PKD, the genetic mutations affect the kidneys primarily, but also affect the development of the liver and other organs.
The genes in every human cell are packed into 46 chromosomes, 23 pairs. We inherit one chromosome of each pair from both our parents, and we can inherit genetic mutations from one or both parents.
PKD disorders are called 'Autosomal' because the mutations occur in one or more of the 22 chromosomal sets that are 'non-sex'. (The 23rd pair are the XY chromosomes that determine gender.) PKD occurs equally in men and women with no gender bias.
The terms 'Dominant' and 'Recessive' refer to the form of inheritance:
- In dominant disorders, you only need to inherit one mutated copy of a gene from one parent to develop a disorder.
- In recessive disorders, you have to inherit two copies of an abnormal gene, one from each parent. If you inherit only one mutated gene, you will be a 'carrier', but not develop the disorder.
ADPKD - AUTOSOMAL DOMINANT POLYCYSTIC KIDNEY DISEASE - is the world’s most common inherited kidney disease, in which fluid-filled cysts develop, multiply and grow in both kidneys. Other organs, such as the liver and brain, may be affected. Between 1 in 400 and 1 in 1000 people worldwide - about 12.5 million - have ADPKD. Over half of those affected will have kidney failure by the time they are 60 years old. Many will experience regular pain, disability and anxiety throughout life. If someone has ADPKD, there is a 1 in 2 (50 percent) likelihood that the disease will pass to each child born.
ARPKD - AUTOSOMAL RECESSIVE POLYCYSTIC KIDNEY DISEASE - is a rare disease that affects the kidneys and liver. It occurs in about one in every 20,000 live births in the UK. ARPKD is a severe disease. Sadly, about one baby in three with ARPKD dies from breathing problems during the first four weeks after birth and some will die during pregnancy. However, 8 to 9 in ten babies (80-90 per cent) who survive the first four weeks of life are still alive at five years old. Encouragingly, a good number of children now survive into adulthood and are able to live full and productive lives.