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Journal of Islamabad Medical & Dental College (JIMDC); 2015:4(1):37-39
Case Report
Bardet-Biedl Syndrome Associated with Dextrocardia
and Situs inversus
Imran Mahmood Khan1, Mohsin Butt2, Waqas Ashfaq3, Saba Naim Khan4, Mehreen Batool5
Assistant Professor, Department of Pediatrics, Islamabad Medical & Dental College, Islamabad
3, 4 Senior Registrar, Department of Pediatrics, Islamabad Medical & Dental College, Islamabad
(Bahria University Islamabad)
1, 2, 5
Abstract
normal vaginal delivery at full term with no antenatal, natal
or postnatal complication. However his developmental
milestones were delayed.
He started walking at 1 year and 10 months. He learned to
speak at 3 years of age. His vision gradually decreased
especially in dim light while hearing and social milestones
were normal. Currently he is studying in main stream school
but his performance is not optimum. His writing and reading
abilities are more affected than his memory. He is the eldest
among the three siblings. His parents and 2 year old sister
are healthy, while one sister who is 5 year old is also having
similar features.
On examination his weight was 29.5 kg at 95th centile,
height was 113cm at 5th centile, BMI 23.10 kg/m2, head
circumference 51.5cm at 50th centile and blood pressure was
130/90 mmHg (both systolic and diastolic blood pressure
above 95th centile). Other findings were short, stubby hands
and feet, polydactyly of all 4 limbs, (Figure 1 and 2) low IQ,
micro penis with normal testes, Talipes equinovarus at birth
which has now been treated successfully with serial casting.
Visual acuity without glasses was 6/60 in right eye and 6/36
in left eye and with glasses 6/12 in both eyes. Fundoscopy
showed retinitis pigmentosa as shown in Figure 3. On
Cardiovascular system examination, apex beat was on right
side in 5th intercostal space, midclavicular line with normal
first and second heart sounds and no murmur.
Bardet-Biedl syndrome is a rare, autosomal recessive inherited
disorder. A few cardinal features of Bardet-Biedl syndrome
include central obesity, hypogonadism, retinitis pigmentosa,
mental retardation, delay of the speech and polydactyly. We
report a case of Bardet-Biedl syndrome with typical phenotype
in conjunction with dextrocardia and Situs inversus with
review of literature.
Key words: Bardet-Biedl syndrome, Hypogonadism,
Obesity, Polydactyly, Retinitis pigmentosa.
Introduction
Bardet-Biedl syndrome (BBS) is a rare autosomal
recessive disorder.1. BBS is named after Georges Louis
Bardet, a French physician (born 1885) and after ArturBiedl,
a Hungarian pathologist and endocrinologist (born 1869)
who described this syndrome in 1920.2 It was later
erroneously coupled with another disorder described by
Laurence and Moon, and was consequently referred to as
Laurence- Moon-Biedl syndrome. BBS is distinguished
from the much rarer Laurence- Moon syndrome, in which
retinal pigmentary degeneration, mental retardation and
hypogonadism occur in conjunction with progressive spastic
paraparesis and distal muscle weakness, but without
polydactyly.3 The principal manifestations are rod-cone
dystrophy (Retinitis pigmentosa), post-axial polydactyly,
central obesity, mental retardation, hypogonadism, and renal
dysfunction.1 We report here a typical case of Bardet-Biedl
syndrome in a seven year old boy with additional finding of
dextrocardia and situs inversus which is rarely seen in
clinical practice.
Case Report
A seven year old male child resident of Kohinoor
Mill, Rawalpindi, presented with complaints of poor vision
Corresponding Author:
Dr Mohsin Butt
Email:[email protected]
Received: March 11th 2015; Accepted: May 5th 2015
Figure 1: Post axial polydactyly of hands.
Laboratory investigations showed raised fasting blood sugar,
fasting serum cholesterol and triglycerides. Blood complete
especially at night, learning difficulties, and rapid weight
gain. He was born from consanguineous marriage, through
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Journal of Islamabad Medical & Dental College (JIMDC); 2015:4(1):37-39
picture, renal function tests, liver function tests and thyroid
function tests were within normal limits.
ophthalmologist and he regularly receives antioxidant
therapy in form of high dose of vitamin A drops at 6 month
interval to slow the progression of retinitis pigmentosa. As
echocardiography showed dextrocardia with situs inversus
and functionally normal heart so no treatment is needed.
His speech is much improved through speech therapy and he
is advised to join special education school to improve his
skills for independent living. Low fat and carbohydrate diet
and regular exercise is advised and he is advised for followup after 3 months. He will specifically need to be followed
up for pubertal development for the next few years as
hypogonadism is a likely problem.
Discussion
Figure 2: Post axial polydactyly of feet.
The prevalence of BBS is 1:160000 in Europe and
North America although higher incidence has been reported
in the isolated populations of Newfoundland [1:13000] and
Kuwait [1:17000].4,5 Incidence is Pakistan is not known. So
far there is no reported case of Bardet-Biedl Syndrome with
Dextrocardia and Situs inversus in world literature although
other congenital heart disease like aortic stenosis, patent
ductus arteriosis, unspecified cardiomyopathy, valvular
stenosis and atrial/ventricular septal defects are the
commonly reported lesions.1 Retinal dystrophy (100%) is
the first major feature of the disorder. It is found
occasionally in the first decade but is present in almost all
patients by the second decade.6 Obesity is the second major
feature of BBS, with a frequency of 72-96% depending on
measurement criteria. Obesity usually begins in childhood
and the severity increases with age. The mean body mass
index (BMI) in females is estimated to be 31.5 mg/m2 while
in males it is 36.6 mg/m2, 6,7
Limb-abnormalities are the third major feature of
BBS. Limb deformities have been reported at varying
frequencies. Of these, post-axial polydactyly, (ulnar side of
the hand and on the fibular side of the foot) and
brachydactyly of both hands and feet are the most common.
Partial syndactyly, fifth finger clinodactyly, and a prominent
gap between the first and second toes are sometimes
associated.1,6 Mental retardation is a more disputed feature
of BBS. Recently, objective IQ tests determined that only a
minority of patients are mentally retarded. The decrease in
IQ level correlates with the presence of visual
handicap.1,7Acquisition of intelligible speech and proper
sentence formation is commonly delayed until age of four
years, but children tend to respond to early therapy.1,7 Hypogenitalism is reported more frequently in BBS males than
females.8 In BBS females, genital abnormalities encompass
a wide range, including hypoplastic fallopian tubes, uterus,
and ovaries, partial and complete vaginal atresia, absent
vaginal orifice, and absent urethral orifice.9 Bardet-Biedl
syndrome males have small penis and testes (88%).9 Renal
failure is the major cause of morbidity and early mortality in
BBS. A wide range of renal abnormalities have been
described. These include chronic renal failure, parenchymal
cysts, calyceal clubbing, fetal lobulation, scarring, unilateral
Figure 3: Retinitis Pigmentosa
Figure 4.Chest x-ray showing dextrocardia and situs
inversus.
Radiological investigations showed dextrocardia on chest xray as shown in Figure 4. Echocardiography showed no
abnormality other than dextrocardia. Ultrasound abdomen
revealed situs inversus with cholelithiasis and no urinary
tract anomalies.
He has been receiving multidisciplinary
management. In infancy, orthopedic surgeon treated
Talipesequinovarus successfully with serial casting. Due to
short stubby feet and polydactyly he cannot wear normal
shoes. So he uses special shoes manufactured by limb centre
of Fauji Foundation Hospital, Rawalpindi. His vision is
much improved with the help of glasses prescribed by
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Journal of Islamabad Medical & Dental College (JIMDC); 2015:4(1):37-39
agenesis, dysplastic kidneys, renal calculi, and vesicoureteric reflux abnormalities.10,11 In 1999, modified
diagnostic criteria were defined after a study conducted in
England in 109 BBS patients.1 According to this criteria
patients who had 4 primary features or 3 primary and 2
secondary features are identified as BBS. Primary features
include rod-cone dystrophy, polydactyly, obesity, learning
disabilities, hypogonadism in males and renal anomalies.
Secondary features include speech disorder/delay,
strabismus/cataracts/astigmatism,
brachydactyly/
syndactyly, developmental delay, polyuria/polydipsia
(nephrogenic
diabetes
insipidus),
ataxia/poor
coordination/imbalance, mild spasticity (especially lower
limbs), diabetes mellitus, dental crowding/ hypodontia/small
roots/high
arched
palate,
left
ventricular
hypertrophy/congenital heart disease and hepatic fibrosis.
Our case had four major and three of the minor criteria thus
fulfilling the diagnostic criteria of Bardet-Biedl syndrome.
Differential diagnosis of BBS include Laurence Moon
syndrome. Alstrom syndrome, Biemond II syndrome, Weiss
syndrome, McKusick-Kaufman syndrome, Senior-Loken
syndrome, Leber congenital amaurosis.3,12,13
Bardet-Biedl syndrome is recessively inherited
with both parents being phenotypically normal. The risk of
subsequent offspring being affected is 25%. There is a 50%
chance that unaffected siblings will be carriers. When a new
case is seen, a careful family history should be taken and
other relatives examined. Management consists of
multidisciplinary approach. The paediatrician should be
involved in the overall care of the patient. The child may
need referral to ophthalmologist, orthopaedic surgeon,
cardiologist, nephrologist, endocrinologist, nutritionist,
speech therapist and occupational therapist.
BBS has an adverse prognosis, with early onset of
blindness, obesity, hypertension, and diabetes mellitus.10
Renal impairment is frequent and often goes undetected
leading to early death in these patients. Their survival and
quality of life depend on the severity of clinical features, as
well as on the quality of the medical care they receive.
Surveillance includes regular ophthalmologic evaluation,
annual blood pressure measurement, monitoring of renal
function, and regular testing for blood sugar levels and lipid
profile.10 These concerns are best addressed in the setting of
a dedicated team made up of the appropriate specialties
allowing proper planning and cooperation so that the patient
may receive the best possible care. The main purpose of this
case report, besides reporting a very rare entity was to make
the reader aware of management strategies and adverse
prognosis. The condition is supposed to be rare, but this may
have been due to the failure to diagnose incomplete or
partial
cases.
Paediatricians,
ophthalmologists,
endocrinologists and nephrologists should be aware of BBS
because of its adverse prognosis.
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