|Year : 2007 | Volume
| Issue : 2 | Page : 76-77
Senior-Loken syndrome in a Saudi child
M Alfadhel1, A Alamir2
1 Division of Genetics, Department of Pediatrics, King Fahad National Guard Hospital, Riyadh, Saudi Arabia
2 Division of Nephrology, Department of Pediatrics, King Fahad National Guard Hospital, Riyadh, Saudi Arabia
Department of Pediatrics, King Fahad National Guard Hospital, P.O. Box 22490, Riyadh 11426
Source of Support: None, Conflict of Interest: None
We present an 11-year-old girl with Senior-Loken syndrome, a rare familial syndrome of retinopathy and nephronophthisis. The patient presented to us with renal insufficiency. There was a strong family history of renal and ocular involvement. This is the first report of this syndrome from the Arabian peninsula.
Keywords: Juvenile nephronophthisis, retinitis pigmentosa, retinopathy, Senior-Loken syndrome
|How to cite this article:|
Alfadhel M, Alamir A. Senior-Loken syndrome in a Saudi child. Indian J Nephrol 2007;17:76-7
| Introduction|| |
Senior-Loken syndrome is a rare syndrome of retinopathy and nephronophthisis. It was first described in 1961 by Senior et al. ; in the same year, Loken et al. described the same condition in two siblings. Henceforth, this syndrome has been called Senior-Loken Syndrome - the clinical feature of this syndrome includes renal involvement, ocular involvement, (retinitis pigmentosa) and other system involvement.
To the best of our knowledge, this is the first report of this syndrome from the Arabian peninsula.
| Case Report|| |
This case of an 11-year-old Saudi female known to have retinitis pigmentosa presented to us with a history of runny nose, vomiting and diarrhea for 2 days. On review of the history of the patient, the patient had symptoms of weakness, polyuria, polydipsia in the last 2 years associated with episodic vomiting, anorexia and weight loss. The parents are first cousins. She has two sisters who are blind and two brothers who are normal and one maternal 18-year-old uncle with blindness and renal failure on dialysis.
On examination, the patient was found to be pale; she was neither jaundiced nor edematous. She was blind and had nystagmus and was afebrile with normal blood pressure. The growth parameter was on 25 th centile for age. Other systemic examination was unremarkable. The laboratory investigation was consistent with the picture of renal failure with anemia, acidosis and impaired renal function; the hemoglobin count was of 6.5 g/dl with normal leukocyte and platelet count. The urea level was 24.5 mmol/l (2.1-7.1 mmol/l); the serum creatinine level, 497 mmol/l (27-62 mmol/l) and serum bicarbonate level, 12 mmol/l (23-29 mmol/l).
Abdominal ultrasound showed bilateral normal-sized echogenic kidneys with mild hydronephrosis, which was consistent with nephronophthisis. There was a single cyst measuring 0.9 cm in the midpole of the left kidney [Figure - 1],[Figure - 2]. The liver and spleen were normal.
Skeletal survey showed osteopenia and multiple tiny calvarial lucencies, which was consistent with renal osteodystrophy.
Based on the clinical picture, the patient was diagnosed as Senior-Loken syndrome and discharged home after discussing with the family regarding the need for a renal transplant as a solution for her renal failure and the renal transplant workup was done for her. The patient was discharged on chronic renal failure medication and the follow-up was conducted in a nephrological clinic.
| Discussion|| |
Senior-Loken syndrome is an autosomal recessive syndrome of retinopathy and nephronophthisis. The renal involvement of this syndrome is well defined.  It is identical to those of isolated nephronophthisis, including course of the renal disease.  Polyuria, polydipsia and impaired concentrating ability are the earliest signs. ,,
Nephronophthisis is usually insidious in nature  and progressive reaching end-stage renal failure before the age of 20 years. However, late onset renal failure in the third and fourth decades is reported. 
Proteinuria is inconsistent and urinary sediment is usually normal; hematuria is not found and the blood pressure remains normal until development of chronic renal failure.
Tubular lesions predominate with defective concentrating ability as an invariable sign; acidifying ability is usually preserved, but hyperchloremic acidosis may occur. Serum electrolytes may be disturbed with hypernatremia, reflecting dehydration.  The histological examination of the kidneys shows fibrosis or diluted tubules with thickened tubular basement membrane and cysts at corticomedullary junction. ,,
Successful renal transplantation has been performed in patients with familial juvenile nephronophthisis without the recurrence of the disease in the transplanted organ.
Ocular involvement takes several forms as follows. Tapetoretinal degeneration: it covers a group of familial and hereditary disorders characterized by progressive degeneration of the choroid and retina, but it varies in its nature and severity and is the commonest.  Leber's congenital amaurosis: it is a severe form leading to blindness in infancy, nystagmus, diffuse atypical fundal pigmentation with pallor of the optic disc, narrowing of the retinal arteries and a flat electroretinogram (ERG). Retinitis pigmentosa: the degeneration begins from external layer of the retina and extends to involve the whole of retinochoroid; the optic fundus is characterized by a stellate mass of pigment in an annular distribution. Other ocular findings include cataract, Coat's disease and keratoconus. 
There are a number of other syndromes associated with nephronophthisis and the findings such as nephronophthisis, retinal dystrophy, severe deafness, diabetes mellitus and obesity constitute Alstrom syndrome;  retinal dystrophy, skeletal deformities and respiratory insufficiency are observed in Jeune's dystrophy; and in Bardet-Biedl syndrome, nephronophthisis may be present.
The retinal lesion in Senior-Loken syndrome is variable and may be severe in infantile onset retinal dystrophy or more typical retinitis pigmentosa.  There are some reports on the association of Senior-Loken syndrome with sensorineural hearing loss, liver fibrosis, cerbellavermis hypoplasia and molar tooth sign on brain MRI.
| References|| |
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|5.||Gleeson JG, Keeler LC, Parisi MA, Marsh SE, Chance PF, Glass IA, et al. Molar tooth sign of the midbrain-hindbrain junction: Occurrence in multiple distinct syndromes. Am J Med Genet A 2004;125:125-34. |
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[Figure - 1], [Figure - 2]