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Fanconi Anaemia - Factsheet fg

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					           Factsheet 
        Fanconi Anaemia
               The titles in this series are intended to provide general information about the topics
                they describe.
               In many cases the treatment of individual patients will differ from that described.
               At all times patients should rely on the advice of their specialist who is the only person
                with full information about their diagnosis and medical history.


        This leaflet should be read                     gene (FA) these are known as FA “A” to
together with the Leukaemia Research                    FA “E”. The FA “C” gene is being studied
Fund booklet Aplastic Anaemia.                          intensively in the laboratory. It is now
                                                        known on which chromosomes the FA “A”
         Fanconi anaemia is a rare                      and “D” genes are located. They have not
inherited form of aplastic anaemia in which             yet been isolated for study.
the bone marrow fails to produce blood
cells normally. The aplastic anaemia is the
most dangerous aspect of Fanconi                          Signs and symptoms
anaemia but there are a number of other
abnormalities often present (see signs and
symptoms).                                                       There is a very wide spectrum of
                                                        disease presentation in Fanconi anaemia,
                                                        related to the 5 different versions of
                                                        abnormal genes. Within families disease
 Causes                                                 may present in childhood, adolescence or
                                                        as adults. Most children with Fanconi
          Fanconi anaemia is an autosomal               anaemia remain well until they are
recessive inherited disease. Autosomal                  between 3 and 12 years old. They then
means the abnormal gene is carried on                   begin to suffer from tiredness (due to
the non-sex chromosomes and so it                       anaemia), infections (due to a low white
affects boys and girls equally. Recessive               count) and bruising or bleeding (due to a
means that it only causes problems if the               low platelet count). In some cases there
child inherits the same defective gene                  may be physical abnormalities typical of
from both parents. A child with one normal              Fanconi anaemia which may be noted at
gene and one affected gene will be                      birth.
clinically unaffected by the disease.
                                                                 These include:
         It has been estimated that the
frequency of carriers is between 1 in 100                            short stature
and 1 in 600 in the general population. In a                         missing thumbs and/or arm bones
family in which both parents are carriers of                         other skeletal anomalies
the Fanconi gene, on average 1 in 4 of                               kidney problems
their children will have completely normal                           abnormal skin coloration
genes, and cannot develop the disease or                             small head or eyes
pass it on, 1 in 4 will have Fanconi                                 learning disabilities
anaemia, and 2 in 4 will have one normal                             low birth weight
                                                                     gut abnormalities
and one affected gene and will be healthy
                                                                     small reproductive organs in males
but will be carriers. Fanconi anaemia is
                                                                     heart defects
more likely to occur after first cousin
marriages.
                                                               The severity of the condition and
                                                        of symptoms may worsen over time.
        There are at least five different
                                                        Fanconi anaemia patients have a
versions of the abnormal Fanconi anaemia
significantly greater risk of developing        Bone Marrow or Stem Cell
leukaemia and other forms of cancer.
                                                Transplant

        They are at particular risk of                   If a well-matched donor is
cancers in areas where body cells               available it may be possible to cure the
normally replace themselves at a high rate      aplastic anaemia by bone marrow or stem
such as the mouth, the lining of the            transplant. If the donor is a sibling i.e.
digestive system, the urinary system and        brother or sister, it is very important to
the reproductive organs. This is probably       confirm, using the chromosome breakage
because the normal Fanconi gene plays a         test, that the donor does not have
very important part in controlling cell         undiagnosed Fanconi anaemia. It may be
growth and division.                            possible to use cord blood stem cells from
                                                a newborn sibling for a transplant.
 Diagnosis
                                                         For more information on
           In some cases the diagnosis of       transplants see the Leukaemia Research
Fanconi anaemia may be suspected at             Fund booklet Bone Marrow and Stem Cell
birth, if the typical physical abnormalities    Transplantation.
are present. This is particularly true if the
parents are already known to carry                      Androgens
Fanconi anaemia genes.
                                                         These are drugs that are artificial
         If a patient is thought to have        versions of male hormones. Between half
Fanconi anaemia then a test called the          and three quarters of Fanconi anaemia
chromosome breakage test will confirm           patients will respond to these drugs. They
the diagnosis. This test is carried out on      tend to improve the red cell count more
lymphocytes from a blood sample. The            than the white cell and platelet counts.
chromosomes in patients with Fanconi            Androgens may prolong life expectancy
anaemia are more easily damaged by              but they are not a cure and most patients
chemicals than normal. This is very             will eventually cease to respond to
important to establish because a number         androgens.
of other diseases can resemble Fanconi
anaemia. The chromosome breakage test
should also be done on the brothers and                  Androgens have severe side
sisters of any Fanconi patient because,         effects, which may include liver damage
even if affected, they may have no              and masculinizing effects in female
symptoms.                                       patients. It may be possible to reduce
                                                these side effects by reducing the drug
          The disease can now be                dosage. For patients treated with
diagnosed before birth if the parents know      androgens very close co-operation with
they are at risk. This requires tests called    doctors and other medical staff is
chorionic villus sampling (CVS) or              particularly important. Growth Factors
amniocentesis. These are difficult tests,
which do carry a slight risk to the unborn               Growth factors are natural
child so they are only done where it is         substances, which control the production
known that there is a definite risk of          of blood cells in the bone marrow. Early
Fanconi anaemia.                                results of clinical trials are positive and
                                                growth factors offer a new form of
                                                treatment to temporarily improve the blood
 Treatment                                      counts. However they do not cure the
                                                condition.
        This section concerns only
                                                 Prognosis
treatment for the aplastic anaemia
component of Fanconi anaemia. If other
problems are present these will require                 See above
other specific treatment.
 Support Groups

Fanconi Anemia Research Fund Inc.
1902 Jefferson, Suite #2
Eugene, OR 97405
USA