Laurence-Moon-Bardet-Biedl Syndrome : A 19 Years Girl with Total Blindness and End Stage Renal Disease

Laurence-Moon-Bardet-Biedl syndrome is a rare autosomal recessive disorder characterized bystructural and functional abnormalities of different organ and tissues. Renal involvement is the single most feature of prognostic importance. We report a case with end stage kidney disease. The diagnosis was missed until patient presented with renal dysfunction. Early diagnosis and screening for renal involvement is crucial for prolong survival.

Amman in 1969 opined Bardet-Biedl syndrome (BBS) is not part of Laurence-Moon syndrome (LMS), rather a distinct entity. 10Confusion exists regarding components of two conditions.Common to both condition are pigmentary change in retina, mental retardation and hypogonadism.Spastic paraparesis is a characteristic feature of LMS. 11 However there is difference in expression of these syndromes, there is overlap between two in clinical feature and some questioned their distinct identity. 12The term LMBBS is still accepted by medical community.As the current patient fulfills almost criteria of both syndromes, for the purpose of this publication, we make no distinction and therefore refer to it as LMBBS throughout.

Case profile:
A 19 years old young girl presented in nephrology department of United Hospital, Dhaka with symptoms of uraemia and fluid overload.She was the 4 th issue of a consanguineous marriage.She was short in height and obese (Fig. -1).She was born with extra digits in her right hand and left foot (fig- 2,3).Her initial motor, mental and other milestone of development was normal.She lost her schooling due to progressive diminution of vision since the age of 8 years and was completely blind at the time of admission.Learning difficulties and intellectual impairments also became evident at the same time.She had five brothers and two sisters.All brothers were alive and healthy, among two; one sister was born with polydactyly in all four limbs and died at the age of 18 months, and other one was of 25 years of age and leading normal life.No relatives were known to have the disease.When family history were explored it was unremarkable in previous generations as far as could be traced.
On examination, she was found to be obese (BMI: 33.3 kg/ m 2 ) (Ht-1.45 m, wt-70 kg) of truncal type, short statured.There was generalized edema with crackles in both lung fields with normal precordium.The blood pressure was 140/80 mm of Hg with regular pulse and normal jugular venous pressure.Investigations revealed hemoglobin of 9.6 gm/dl, blood urea 153 mg/dl (Normal 15-45 mg/dl) and serum creatinine was 7.2 mg/dl (Normal 0.6-1.5 mg/dl).sodium 140 mmol/l, potassium 8 mmol/l, chloride 99 mmol/l.Ultrasonography revealed both kidneys smaller in size, measuring 71X 53mm (right kidney) and 72 X 51mm (left kidney), parenchymal thickness of RK is 9 mm and LK is 8mm, increased cortical echogenicicty with poor cortex and medulla differentiation (fig- 4).Patient's party refused to do renal biopsy.ECG, Echocardiography, EEG and CT scan brain were normal.
Subsequently she was put on haemodialysis.After recovery from ureamic encephalopathy it was found she had no perception of light in both eyes, and bilateral gaze-evoked nystagmus was present.Ophthalmoscopic examination showed bilateral optic atrophy and diffuse hypo and hyperpigmentation sparing the macular area, as well as bone spicules in the mid peripheral retina (retinitis pigmentosa).Her IQ was low (< 60) and secondary sexual characters were not well developed.She was advised maintenance haemodialysis before successful renal transplantation done.She underwent maintenance dialysis in her native place.Patient died following missed periods of dialysis 6 month after diagnosis.

Discussion:
LMBBS is autosomal recessive disorder.Some genetic linkage on certain chromosome has been found but their role is yet to be fully known.Interfamilial marriage is another risk factor.LMBBS affects approximately 1 in 100,000 babies born.The Bedouins of Kuwait and Newfouland area has high prevalence. 13r patient was also born of a consanguineous wedlock.Probably her sister which died at early age was also affected.And cases showed different members being affected in a single family.Earlier reports of Laurence and Moon, Biedl described affection of several siblings.Because of diverse systemic involvement it can present to any specialty.5] While these two cases were male our patient was female and diagnosed late probably because of rare occurrence of the disease.Such delayed diagnosis until patient presenting with end stage renal disorder was documented by other observers. 1ly in the last 20 years significant renal abnormality has been reported with this syndrome.Urologic abnormality has been reported in 90% patients with normal renal function.A significant number of patients (30%) develop symptoms or signs of renal disease ranging from recurrent urinary tract infections (associated with reflux) to chronic renal failure.Renal tubular dysfunction is also common. 1 A report suggested incidence of ESRD as 4% in LMBBS. 15nal involvement is the prognostically most significant.c though incidence is low, presence of ESRD defines prognosis of individual.Death from ESRD usually observed in third or fourth decade. 1 Upto 2007 only 8 cases were described in Indian literature with only one having ESRD. 16 As patient's party denied renal biopsy; exact histological nature of renal involvement remained undetermined.Chronic interstitial nephritis, mesangial proliferative glomerulopathy, and ultrastructural changes in the glomerular basement membrane has been described in various reports. 15nagement of BBS is supportive and includes training and rehabilitation for blind and mentally retarded patients, hearing aids for deafness, and diet and exercise for obesity.Surgical correction can be undertaken for polydactyly.Organizations can provide emotional and social support and help in all-round development.Early and regular screening for hypertension, diabetes, and renal involvement is required. 10The management of renal failure does not differ from that due to any other cause.All modalities of long-term renal replacement therapy, i.e., dialysis, and renal transplantation can be offered to these individuals. 15

Conclusion:
We described a case of LMBBS with end stage renal disease.Renal failure being the commonest cause of death in this condition.However supportive management can prolong the survival.The diagnosis should be considered in patients with characteristic phenotypes.Early and regular screening for hypertension, diabetes, and renal involvement is required.