Home About us Editorial board Search Ahead of print Current issue Archives Submit article Instructions Subscribe Contacts Login 
Print this page Email this page Users Online: 3350

  Table of Contents  
CASE REPORT
Year : 2014  |  Volume : 7  |  Issue : 2  |  Page : 198-200  

Rare cause of pediatric obesity: Bardet - Biedl Syndrome


Department of Pediatrics, PDU Medical College, Rajkot, Gujarat, India

Date of Web Publication4-Feb-2014

Correspondence Address:
Mitul B Kalathia
131, Chitrakutdham Society, Kalawad Road, Rajkot - 360 005, Gujarat
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0975-2870.126341

Rights and Permissions
  Abstract 

Bardet - Biedl syndrome (BBS) is a rare autosomal recessive disorder, characterized by central obesity, retinal pigmentation, polydactyly, mental retardation, hypogonadism, and renal dysfunction. Other features may include deafness, diabetes mellitus, genitourinary abnormalities, short stature, hormonal abnormalities, developmental defects, and speech problems. We report a case of BBS who presented with night blindness, marked central obesity, polydactyly, syndactyly, hypogonadism, micropenis, and behavioral problems, along with a brief review of the literature.

Keywords: Bardet - Biedl syndrome, hypogonadism, obesity, polydactyly


How to cite this article:
Kalathia MB, Parikh YN, Parmar PN, Verma SS. Rare cause of pediatric obesity: Bardet - Biedl Syndrome. Med J DY Patil Univ 2014;7:198-200

How to cite this URL:
Kalathia MB, Parikh YN, Parmar PN, Verma SS. Rare cause of pediatric obesity: Bardet - Biedl Syndrome. Med J DY Patil Univ [serial online] 2014 [cited 2017 May 23];7:198-200. Available from: http://www.mjdrdypu.org/text.asp?2014/7/2/198/126341


  Introduction Top


Bardet-Biedl syndrome (BBS) is a rare autosomal recessive disorder, characterized by central obesity, retinal pigmentation, polydactyly, mental retardation, hypogonadism, and renal dysfunction. Other features are deafness, diabetes mellitus, genitourinary abnormalities, short stature, hormonal abnormalities, developmental defects, and speech problems. [1],[2]

We report a case of BBS who presented with night blindness, marked central obesity, polydactyly, syndactyly, hypogonadism, micropenis, and behavioral problems, along with a brief review of the literature.


  Case Report Top


A 12-year-old boy presented to the pediatric outpatient department with the complaint of night blindness. His height and weight were 138 cm (>97 th percentile) [3] and 71 kg (>97 th percentile), [3] respectively, with a resultant body mass index of 41 (>95 th percentile) [3] that indicated severe obesity [Figure 1]. Hexadactyly was present in both lower limbs, along with syndactyly of fifth finger in the left upper limb and malformed fifth finger in the right upper limb [Figure 2] and [Figure 3]. Our patient had low testicular volume of 2 ml (normal 10-12 ml) and micropenis (<2.5 cm) [Figure 4]. Secondary sexual characteristics (pubic hairs, facial hairs, voice change) were absent. School performance of the child was poor, and the child had behavioral problems. Developmental milestones of our case were delayed with an intelligent quotient (IQ) of 75.
Figure 1: Central obesity in a case of Bardet - Biedl syndrome

Click here to view
Figure 2: Polydactyly (hexadactyly) of both lower limbs

Click here to view
Figure 3: Syndactyly of fifth finger in the left upper limb and malformed fifth finger in the right upper limb

Click here to view
Figure 4: Hypogonadism and micropenis with absent pubic hairs and scrotal growth

Click here to view


On ophthalmological examination, visual acuity was 6/36 in both eyes. Fundus examination showed pallor and atrophy of the optic disk, with retinal pigmentary changes. Hearing assessment of the child was normal. Investigations such as hemogram, renal function tests, liver function tests, lipid profile, blood glucose, postprandial blood sugar, and urine sugar were normal. An ultrasound revealed normal kidney morphology.

Parents of the child were advised regarding genetic counseling and testing. Child and his parents were advised regarding probable morbidities and were also advised regular follow-up to observe for renal dysfunction, diabetes and its management, if required. Puberty is a particularly stressful time for those with BBS. We referred the patient to a counselor for behavioral problems. There is no proven effective treatment to either prevent or improve the outcome in vision. A low-calorie and low-fat diet was advised to control obesity as per the dietitian's recommendations, and physical exercises were stressed upon.


  Discussion Top


BBS is relatively rare and less than 20 cases have been reported from India. [4] Beales et al. developed the diagnostic criteria for BBS, according to which presence of four primary features or three primary features and two secondary features is considered for diagnosis of BBS. [2] The primary features include central obesity, retinopathy, polydactyly, mental retardation, hypogonadism, and renal dysfunction, while the secondary features are deafness, diabetes mellitus, genitourinary abnormalities, hormonal abnormalities, short stature, developmental defect, and speech deficits. [1],[2]

Retinopathy occurs in 90% of the patients. Maculopathy associated with disk pallor develops in late childhood. Retinal dysfunction usually becomes apparent at age 7-8 years, when night blindness gradually starts. [2] Macula is involved by second or third decade of life in all individuals, with visual acuity of 20/200 or worse. [5],[6] Other ophthalmological findings include nystagmus, strabismus, high myopia, cataract, and glaucoma. [1],[2]

Postaxial polydactyly is common, but not invariable. [2]

Brachydactyly of the fingers and toes is common. Other findings may include partial syndactyly (most usually between the second and third toes), fifth finger clinodactyly, and a prominent "sandal gap" between the first and second toes. [7]

Obesity is a common feature in almost all the patients. Birth weight is usually normal in individuals with BBS. Significant weight gain begins in infancy and becomes a lifelong issue. The distribution of adipose tissue is more prominent in the trunk and proximal limbs in adulthood. [1],[2],[8] Intellectual disability has been described as a major feature of BBS, but the difficulty of vision while assessing cognitive functions is often ignored. Most individuals have significant learning difficulties and only a minority have severe impairment on IQ testing. [2],[9]

Hypogonadism is more frequent in males than females with BBS. Hypogonadism in females results in failure of development of secondary sexual characteristics and delayed menarche. Males have micropenis at birth, with small-volume testes. Affected females may have malformations of fallopian tubes, uterus, and ovaries. Other complex anomalies of the female genitourinary tract may include complete vaginal atresia, septate vagina, duplex uterus, hematocolpos, persistent urogenital sinus, vesico-vaginal fistula, absent vaginal orifice, and absent urethral orifice. [1],[2]

Progressive renal damage occurs in BBS and can lead to end-stage renal disease necessitating renal replacement therapy or transplantation. [1],[10] Hypertension may occur in 50-66% of the affected individuals. [1],[2]

Speech development is delayed with sentence formation beyond 4 years and various problems in speech is found even in adult patients. [2],[9] Neurological abnormalities in the form of ataxia and impaired coordination are encountered. [2],[8] Psychiatric problems like anxiety, mood disorders, depression, bipolar disorder, obsessive compulsive behavior, and psychosomatic manifestations are observed. [2],[9]

Genes associated with BBS are BBS1, BBS2, ARL6 (BBS3),

BBS4, BBS5, MKKS (BBS6), BBS7, TTC8 (BBS8), BBS9, BBS10, TRIM32 (BBS11), BBS12, MKS1 (BBS13), and CEP290 (BBS14). Molecular genetic testing is available for all these BBS-related genes. [1],[9] Prenatal diagnosis for pregnancies at increased risk for BBS can be done by genetic testing of sample obtained by amniocentesis or chorionic villus sampling. [1],[9]

Prenatal diagnosis using second trimester ultrasound examination in pregnancies at risk to detect anomalies such as postaxial polydactyly and renal cysts found in BBS has been reported. [11] Prenatal appearance of big hyperechoic kidneys with no corticomedullary differentiation should be considered recurrence of BBS. [11] In pregnancies not at increased risk, presence of polydactyly along with the above-mentioned antenatal ultrasound renal anomalies is considered as having BBS syndrome. [11]

 
  References Top

1.Waters AM, Beales PL. Bardet-Biedl Syndrome. 2003 Jul 14. In: Pagon RA, Adam MP, Bird TD, editors. GeneReviews [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2013. Available from: http://www.ncbi.nlm.nih.gov/books/NBK1363/ [Last updated on 2011 Sep 29].  Back to cited text no. 1
    
2.Beales PL, Elcioglu N, Woolf AS, Parker D, Flinter FA. New criteria for improved diagnosis of Bardet-Biedl syndrome: Results of a population survery. J Med Genet 1999;36:437-4.  Back to cited text no. 2
    
3.Khadilkar VV, Khadilkar AV, Choudhury P, Agarwal KN, Ugra D, Shah NK. Writing group.IAP Growth Monitoring Guidelines for Children from Birth to 18 Years Indian Pediatrics 2007;44:187-97.   Back to cited text no. 3
    
4.Hooda AK, Karan SC, Bishnoi JS, Nandwani A, Sinha T. Renal transplant in a child with Bardet-Biedl syndrome: A rare cause of end-stage renal disease. Indian J Nephrol 2009;19:112-4.  Back to cited text no. 4
[PUBMED]  Medknow Journal  
5.Heon E, Westall C, Carmi R, Elbedour K, Panton C, Mackeen L, et al. Ocular phenotypes of three genetic variants of Bardet-Biedl syndrome. Am J Med Genet A 2005;132:283-7.  Back to cited text no. 5
    
6.Klein D, Ammann F. The syndrome of Laurence-Moon-Bardet-Biedl and allied diseases in Switzerland. Clinical, genetic and epidemiological studies. J Neurol Sci 1969;9:479-513.  Back to cited text no. 6
    
7.Ramirez N, Marrero L, Carlo S, Cornier AS. Orthopaedic manifestations of Bardet-Biedl syndrome. J Pediatr Orthop 2004;24:92-6.  Back to cited text no. 7
    
8.Grace C, Beales P, Summerbell C, Jebb SA, Wright A, Parker D, et al. Metabolism in Bardet-Biedl syndrome. Int J Obes Relat Metab Disord. 003;27:1319-24.  Back to cited text no. 8
    
9.Moore SJ, Green JS, Fan Y, Bhogal AK, Dicks E, Fernandez BA, et al. Clinical and genetic epidemiology of Bardet-Biedl syndrome in Newfoundland: A 22 year prospective,population-based, cohort study. Am J Med Genet A 2005;132:352-60.  Back to cited text no. 9
    
10.Harnett JD, Green JS, Cramer BC, Johnson G, Chafe L, McManamon P, et al. The spectrum of renal disease in Laurence Moon Biedl syndrome. N Engl J Med 1988;319:615-8.  Back to cited text no. 10
    
11.Cassart M, Eurin D, Didier F, Guibaud L, Avni EF. Antenatal renal sonographic anomalies and postnatal follow up of renal involvement in Bardet Biedl syndrome. Ultrasound Obstet Gynecol 2004;24:51-4.  Back to cited text no. 11
    


    Figures

  [Figure 1], [Figure 2], [Figure 3], [Figure 4]



 

Top
   
 
  Search
 
    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Access Statistics
    Email Alert *
    Add to My List *
* Registration required (free)  

 
  In this article
Abstract
Introduction
Case Report
Discussion
References
Article Figures

 Article Access Statistics
    Viewed68844    
    Printed35    
    Emailed1    
    PDF Downloaded237    
    Comments [Add]    

Recommend this journal