are no genetic tests or diagnostic procedures that
conclusively diagnose familial Mediterranean
fever; the doctor makes the diagnosis on the basis
of family history and the pattern of symptoms.
See also AUTOSOME; GENETIC DISORDERS; INHERI-
TANCE PATTERNS; MUTATION; RENAL FAILURE.
family medical pedigree A comprehensive list-
ing of relatives and their medical conditions,
including information about diseases that may
have genetic foundations. A family medical pedi-
gree looks somewhat like a genealogic family tree,
with branched lineage to show family relation-
ships (such as marriage, birth, half-siblings). The
family medical pedigree should extend at least
three generations and list each person’s age at the
time of death, the cause of death, and any known
history of diseases or symptoms.
Many of the health conditions doctors know
today are genetic in origin were not known, either
as diseases or as GENETIC DISORDERS, even one or
two generations ago, so documenting symptoms
can help reveal undetected genetic conditions.
Maintaining a record of personal health symptoms
and conditions, and similar information for chil-
dren, can further provide important clues about
genetic factors in health and in illness.
See also GENOME; INHERITANCE PATTERNS; MUTATION;
PERSONAL HEALTH HISTORY.
fragile X syndrome An inherited genetic disor-
der that results in significant intellectual impair-
ment. Fragile X syndrome arises from a
monogenic (single-GENE), increased repeat MUTA-
TIONaffecting the FMR1 gene on the X CHROMO-
SOME and is the leading cause of inherited
intellectual impairment in males. Fragile X syn-
drome more severely affects males because
females have a second X chromosome that can
somewhat override the mutated gene on the other
X chromosome. Most females are unaffected carri-
ers. Because males have one X chromosome and
one Y chromosome, they lack this dampening
affect. A male can also be an unaffected CARRIERof
the mutated gene, though this is very rare, and
will thus pass the mutation to all of his daughters
though none of his sons.
The symptoms of fragile X syndrome vary in
severity though typically include- developmental delays
- speech impairments
- intellectual impairment (sometimes profound)
- seizures
- behavioral problems
- AUTISM-like characteristics
- physical features that may include overly flexi-
ble joints, flat feet, long facial configuration,
and oversized ears
Diagnosis occurs through GENETIC TESTING, typi-
cally cytogenic analysis. Treatment may include
supportive measures such as special education in
school, speech and language pathology, and med-
ications to moderate behaviors and control
seizures. Children who are mildly affected may
require little extra care and may attend regular
classes and schools; those who are severely
affected may require ongoing support and institu-
tional care.
See also DOWN SYNDROME; GENETIC COUNSELING;
GENETIC DISORDERS; INHERITANCE PATTERNS; PHENYLKE-
TONURIA(PKU); SEIZURE DISORDERS.126 Genetics and Molecular Medicine