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What are some important questions parents should ask at their first appointment with a pediatric nephrologist after the initial diagnosis of ARPKD?
- What is the current renal function?
- How do we decrease the progression of CKD?
- Are there consequences (anemia, renal osteodystrophy, electrolyte abnormalities, hypertension, acidosis, growth failure) at this time and if so, what do we do to control these?
- How is the liver doing?
- When should we follow up with you (the nephrologist)?
- How often should we monitor the blood pressure?
- What numbers are we looking for in the blood pressure readings?
- Are there any dietary or physical restrictions at this point?
- What are things we should look out for and/or be concerned enough about to call the pediatrician?
- Do I have to be concerned if my child has a fever?
- Are there other specialists we should see?
- Are you satisfied with my child's growth?
What kinds of medications might my child need to take daily and weekly?
ARPKD children will likely have to take blood pressure medication daily. Other common supplements include Vitamin D, iron, bicarbonate and citrate. Anemic children may need additional medications. Children experiencing growth problems may take growth hormone, if proper nutrition isn't helping.
How often will my child need to see a doctor?
Your pediatric nephrologist will tailor the frequency of visits to your child's needs, depending on the severity and course your child's disease is taking. Some children may need several visits a year, while others may require only one visit a year. If a child's blood pressure needs a lot of attention, he or she may need to be seen more often. When the kidney function has fallen to levels where dialysis or transplantation is necessary, extra visits will be required.
What kinds of doctors might my child need to see?
A pediatric nephrologist is a specialist who has been trained in the care of children with kidney diseases. It is important that this type of doctor is involved with your child, since ARPKD is such an uncommon disease. Children who also show symptoms of liver disease (CHF), may also need to see a hepatologist. Sometimes ARPKD children require a lung specialist too. Parents recommend finding a pediatrician who isn't afraid to help manage a child with special needs; the right pediatrician can make a great addition to the health care team. Other doctors your child may need to see include a nutritionist or renal dietitian and an endocrinologist if your child needs growth hormone.
How can I find doctors experienced in treating children with ARPKD?
Your child's pediatrician is your first point of reference and should refer you to an experienced pediatric neprohologist in your area. Very often it is necessary to travel to see the pediatric nephrologist for an initial evaluation and then to visit at intervals. Between those visits the pediatric nephrologist and your pediatrician can coordinate your child's specific care. It is very important that your pediatrician be skilled in handling high blood pressure in children. If your pediatrician can't refer you to a pediatric nephrologist or you'd like a second opinion, you may want to contact the PKD Foundation ARPKD Chapter Coordinators at ARPKDChapter@pkdcure.org.
Another option: The American Society of Pediatric Nephrology (www.aspneph.com) has indicated families who need assistance in locating a doctor to familiar with kidney issues in children can send an email to email@example.com. When contacted by families, the organization will provide a listing of all pediatric nephrologists in the family's home state.
If my child dies from ARPKD, should I have his/her cord blood preserved for genetic testing?
Although the gene responsible for ARPKD has been identified and cloned, a simple diagnostic test that can be used clinically to assist in the diagnosis of the disorder is not available. In part, this is related to the very large size of the gene. However, while it may not currently be recommended to preserve cord blood or DNA from a child at risk for having ARPKD for diagnostic purposes, improvements in genetic testing capabilities makes this a question that should be posed to your physician.
In addition to blood cord testing, parents also recommend requesting an autopsy to help diagnose future pregnancies which may be affected by ARPKD.
Should I tell my children they have or are at risk for ADPKD?
To date, no research has been done on the effect such knowledge would have on children. Generally speaking, there is no need to burden children with information they are too young to understand. Children have a tendency to ask questions when situations arise, and, at that time, children usually want simple, honest answers. There is no need to go into great detail unless a child asks more questions on the subject.
Children of affected parents need not be tested for ADPKD. They may be monitored by their physicians for blood pressure, urinalysis and general health without actually making the ADPKD diagnosis. The decision parents make to test a child should recognize the fact that a negative result in childhood may not exclude the diagnosis later in life. The added consequences of making the diagnosis in childhood may give the child a label which will result in discrimination in employment and possibly in health and life insurance. Children can be informed of their risk for ADPKD, but routine screening is not recommended at this time. When and if therapies become available to prevent the progression of cystic kidney disease, then the decision to screen may change.
What types of genetic testing are available for families affected by ARPKD or ADPKD?
According to the National Institutes of Health (NIH) National Human Genome Research Institute, reproductive genetic testing generally involves the following categories of tests:
- Carrier testing is performed to determine whether an individual carries one copy of an altered gene for a particular recessive disease. The term recessive refers to diseases that will occur only if both copies of a gene that an individual receives have a disease-associated mutation; thus, each child born to two carriers of a mutation in the same gene has a 25 percent risk of being affected with the disorder. Couples are likely to have carrier tests if they are at higher risk of having a child with a specific disorder because of their racial or ethnic heritage or family history. Carrier testing is often done in the context of family planning and reproductive health.
- Preimplantation diagnosis is used following in vitro fertilization to diagnose a genetic disease or condition in a preimplantation embryo. Preimplantation genetic diagnosis is essentially an alternative to prenatal diagnosis, as it allows prenatal testing to occur months earlier than conventional tests such as amniocentesis ¿ even before a pregnancy begins. Doctors can test a single cell from an eight-cell embryo that is just days old to determine, among other things, whether it is a male or female. This can provide crucial information for genetic diseases that afflict just one sex. Some patients receiving preimplantation genetic diagnosis are those at risk of transmitting a single gene disorder to their offspring. The number of monogenic disorders that have been diagnosed in preimplantation embryos has increased each year.
- Prenatal diagnosis is used to diagnose a genetic disease or condition in a developing fetus. The techniques currently in use or under investigation for prenatal diagnosis include (1) fetal tissue sampling through amniocentesis, chorionic villi sampling (CVS), percutaneous umbilical blood sampling, percutaneous skin biopsy, and other organ biopsies, including muscle and liver biopsy; (2) fetal visualization through ultrasound, fetal echocardiography, embryoscopy, fetoscopy, magnetic resonance imaging, and radiography; (3) screening for neural tube defects by measuring maternal serum alpha-fetoprotein (MSAFP); (4) screening for fetal Down syndrome by measuring MSAFP, unconjugated estriol, and human chorionic gonadotropin; (5) separation of fetal cells from the mother's blood; and (6) preimplantation biopsy of blastocysts obtained by in vitro fertilization. The more common techniques are amniocentesis, performed at the 14th to 20th week of gestation, and CVS, performed between the 9th and 13th week of gestation. If the fetus is found to be affected with a disorder, the couple can plan for the birth of an affected child or opt for elective abortion.
- Newborn screening is performed in newborns on a public health basis by the states to detect certain genetic diseases for which early diagnosis and treatment are available. Newborn screening is one of the largest public health activities in the United States. The goal of this screening is to identify affected newborns quickly in order to provide treatment that can prevent mental retardation, severe illness or death.
It is possible that somatic cell nuclear transfer (cloning) techniques could eventually be employed for the purposes of reproductive genetic testing. In addition, germline gene transfer is a technique that could be used to test and then alter the genetic makeup of the embryo. To date, however, these techniques have not been used in human studies.
What are the ethical issues involved in genetic testing?
Again citing the NIH, any procedure that provides information that could lead to a decision to terminate a pregnancy is not without controversy. Some ethicists are concerned that the ability to eliminate potential offspring with genetic defects contributes to making society overall less tolerant of disability. Others have argued that prenatal diagnosis is sometimes driven by economic concerns because as a society we have chosen not to provide affordable and accessible health care to everyone. Thus, prenatal diagnosis can save money by preventing the birth of defective and costly children. For reproductive genetic procedures that involve greater risk to the fetus, e.g., preimplantation diagnosis, concerns remain about whether the diseases being averted warrant the risks involved in the procedures themselves. These concerns are likely to escalate should cloning or germline gene transfer be undertaken as a way to genetically test and select healthy offspring.
How can I find a hospital or medical clinic that conducts genetic testing?
A list of clinic conducting genetic testing for ARPKD can be found through a free resource here funded by the NIH.
According to the NIH, all laboratory tests performed for the purpose of providing information about the health of an individual must be conducted in laboratories certified under the Clinical Laboratory Improvements Act. The Centers for Disease Control (CDC) has a role in addressing the public health impact of advances in genetic research, furthering the collection, analysis, dissemination, and use of peer-reviewed epidemiologic information on human genes and coordinating the translation of genetic information into public health research, policy and practice. All laboratory tests and their components are subject to FDA oversight under the Federal Food, Drug and Cosmetic Act. Under this law, laboratory tests are considered to be diagnostic devices, and tests that are packaged and sold as kits to multiple laboratories require pre-market approval or clearance by FDA. However, according to the Secretary's Advisory Committee on Genetic Testing, most new genetic tests are being developed by laboratories and are being provided as clinical laboratory services. These tests are referred to as in-house tests or "home brews." The current administration is examining whether FDA has authority, by law, to regulate such tests.
Will my child develop CHF?
Yes, all children with ARPKD develop some degree of CHF, congenital hepatic fibrosis.
What is CHF?
CHF is malformation of the bile ducts that is sometimes referred to as Ductal Plate Malformation. This malformation is associated with biliary ectasia (bile duct dilatation) and scarring of the liver in the portal tracts, which carry blood to the liver and bile away from the liver.
How does someone get CHF?
It is an inherited defect which affects both the liver. It is uncommon for a person to have CHF without ARPKD or another renal cystic disease. However, if a person has ARPKD they always have some degree of CHF.
What effect can CHF have?
The portal vein, which carries large amounts of blood to and through the liver, and the bile ducts, which carry bile away from the liver, are both part of the "plumbing system" They normally have unrestricted flow, but with CHF this may be greatly reduced as these areas fill with scar tissue (fibrosis) creating blood flow resistance and turbulence.
What is the impact of CHF?
CHF has the potential to cause severe clinical liver complications. Slow blood flow results in a "backup pressure" within the vessels that feed the portal vein. This backup pressure results in increased pressure in the portal vein (portal hypertension). This can lead to mild to massive gastrointestinal bleeding, low white cell counts, low hemoglobin and low platelet counts (from hypersplenism). CHF may also be complicated by cholangitis. Cholangitis is an infection of the common bile duct, the tube that carries bile from the liver to the gallbladder and intestines. CHF may also cause ascites, excess fluid in the space between the tissues lining the abdomen and abdominal organs (the peritoneal cavity). Ascites due to liver disease is caused by high pressure in the blood vessels of the liver (portal hypertension) and low albumin levels. Varices, swollen veins in the esophagus and upper stomach, can also be caused by CHF.
What is Caroli's Syndrome?
Many professionals consider Caroli's Syndrome part of the CHF spectrum.
What do doctors think of doing a liver biopsy in a child with ARPKD/CHF?
Liver biopsy in CHF is controversial; in general, most doctors who treat ARPKD patients do not recommend a liver biopsy to make the diagnosis of CHF. Doctors say there is no validated system to diagnose or stage CHF by biopsy and they can assess severity using noninvasive means instead.