Mental retardation, pigmentary retinopathy,
polydactyly, obesity, renal anomalies, and hypogenitalism.
Biedl Syndrome. Often incorrectly called (and confused
with) Laurence-Moon-Bardet-Biedl Syndrome, which first should be called
Laurence Moon Syndrome and second is a separate entity presenting with
Sex ratio 1:1. Increased in the Arab population of
Kuwait (among the Bedouins) with an estimated (minimal) prevalence of
Autosomal recessive. Consanguinity of parents
not uncommon. Several types of Bardet-Biedl syndrome (BBS) have been
identified. BBS-1 is linked to 11q13 and BBS-2 maps to 16q21, whereas BBS-3,
BBS-4, and BBS-5 map to 3p13-p12, 15q22.3-q23, and 2q31, respectively. BBS-6
is linked to a mutation on 20p12. Heterozygotes have an increased frequency
of obesity, hypertension, diabetes mellitus, and renal disease. Hepatic
fibrosis may occur in homozygotes.
Hypogonadism of central origin combined with a
decreased level of growth hormone.
Cardinal signs of the syndrome are obesity,
hypogenitalism, polydactyly, mental retardation, and retinal dystrophy.
The different types of BBS vary mainly in their
degree of mental retardation, obesity, and distribution of polydactyly (may
occur on all four extremities, only on two, or even be absent). Polydactyly,
brachydactyly, and syndactyly of hands and/or feet, but also short broad
bones and flat joint surfaces of the metacarpophalangeal or
metatarsophalangeal joints (short, broad feet) are common. Renal functional (renal
insufficiency with increased fractional sodium excretion) and structural
abnormalities (calyceal cysts, diverticula, clubbing and blunting, abnormal
[fetal] lobulation). Intact urine acidification, no proteinuria, glycosuria,
or hyperaminoaciduria. End-stage renal failure seems to be uncommon.
Hypogenitalism in males with serum testosterone levels lower than the levels
of compared obese but otherwise normal children. Testosterone level fails to
respond to human chorionic gonadotropin therapy. Although infertility is
common, some male patients reportedly are fertile. In females, vaginal
atresia and hypoplasia of the uterus were reported. Diabetes mellitus,
hypercholesterolemia, and arterial hypertension may be present. Cardiac anomalies
(hypertrophy of the interventricular septum and left ventricle, dilated
cardiomyopathy) are reported in up to 50% of patients. Hepatic fibrosis
is common. Retinal dystrophy (only a few cases with typical retinitis
pigmentosa) results in elevation of dark adaptation threshold with night
blindness by approximately 4 years of age, progressing to visual problems
during daytime at approximately 6 to 7 years of age. None of the patients older
than 16 years had a best-corrected visual acuity higher than 0.1, and many
were classified as legally blind. A higher frequency of hypodontia, small
teeth with short roots, and higher buffering capacity of saliva was
Evaluation of renal and cardiac
function. Check blood glucose level to exclude hyperglycemia.
Because of renal dysfunction,
dehydration must be prevented. Cardiac function must be evaluated before and
throughout anesthesia, with close followup of blood pressure, urinary
output, and plasma glucose levels. As a consequence of obesity, the
anesthesiologist must expect difficult vascular access, ventilation, and
tracheal intubation. As a result of increased risk of aspiration ...