Clinical spectrum of primary hyperoxaluria type 1: Experience of a tertiary center.
OBJECTIVE
Primary hyperoxalurias are rare inborn errors of metabolism resulting in increased endogenous production of oxalate that leads to excessive urinary oxalate excretion. Diagnosis of primary hyperoxaluria type 1 (PH1) is a challenging issue and depends on diverse diagnostic tools including biochemical analysis of urine, stone analysis, renal biopsy, genetic studies and in some cases liver biopsy for enzyme assay. We characterized the clinical presentation as well as renal and extrarenal phenotypes in PH1 patients.


METHODS
This descriptive cohort study included patients with presumable PH1 presenting with nephrolithiasis and/or nephrocalcinosis (NC). Precise clinical characterization of renal phenotype as well as systemic involvement is reported. AGXT mutational analysis was performed to confirm the diagnosis of PH1.


RESULTS
The study cohort included 26 patients with presumable PH1 with male to female ratio of 1.4:1. The median age at time of diagnosis was 6 years, nevertheless the median age at initial symptoms was 3 years. Thirteen patients (50%) were diagnosed before the age of 5 years. Two patients had no symptoms and were diagnosed while screening siblings of index patients. Seventeen patients (65.4%) had reached end-stage renal disease (ESRD): 6/17 (35.3%) during infancy, 4/17 (23.5%) in early childhood and 7/17 (41.29%) in late childhood. Two patients (7.7%) had clinically manifest extra renal (retina, heart, bone, soft tissue) involvement. Mutational analysis of AGXT gene confirmed the diagnosis of PH1 in 15 out of 19 patients (79%) where analysis had been performed. Fifty percent of patients with maintained renal functions had projected 10 years renal survival.


CONCLUSIONS
PH1 is a heterogeneous disease with wide spectrum of clinical, imaging and functional presentation. More than two-thirds of patients presented prior to the age of 5 years; half of them with the stormy course of infantile PH1. ESRD was the commonest presenting manifestation in two-thirds of our cohort.
Department of pediatrics, Kasr Al Ainy School of Medicine, Cairo University, 2, Elrasheed street, Mounira, 11617 Cairo, Egypt; EGORD, Egyptian group of orphan renal diseases, 2, Elrasheed street, Mounira, 11617 Cairo, Egypt; Center of pediatric nephrology and transplantation, Cairo University, 2, Elrasheed street, Mounira, 11617 Cairo, Egypt. Electronic address: nsoliman@kasralainy.edu.eg.
Neveen A
NA
Soliman
Department of pediatrics, Kasr Al Ainy School of Medicine, Cairo University, 2, Elrasheed street, Mounira, 11617 Cairo, Egypt; EGORD, Egyptian group of orphan renal diseases, 2, Elrasheed street, Mounira, 11617 Cairo, Egypt; Center of pediatric nephrology and transplantation, Cairo University, 2, Elrasheed street, Mounira, 11617 Cairo, Egypt.
Marwa M
MM
Nabhan
Department of pediatrics, Kasr Al Ainy School of Medicine, Cairo University, 2, Elrasheed street, Mounira, 11617 Cairo, Egypt; EGORD, Egyptian group of orphan renal diseases, 2, Elrasheed street, Mounira, 11617 Cairo, Egypt; Center of pediatric nephrology and transplantation, Cairo University, 2, Elrasheed street, Mounira, 11617 Cairo, Egypt.
Safaa M
SM
Abdelrahman
Department of pediatrics, Kasr Al Ainy School of Medicine, Cairo University, 2, Elrasheed street, Mounira, 11617 Cairo, Egypt; EGORD, Egyptian group of orphan renal diseases, 2, Elrasheed street, Mounira, 11617 Cairo, Egypt; Center of pediatric nephrology and transplantation, Cairo University, 2, Elrasheed street, Mounira, 11617 Cairo, Egypt.
Hanan
H
Abdelaziz
Department of pediatrics, Kasr Al Ainy School of Medicine, Cairo University, 2, Elrasheed street, Mounira, 11617 Cairo, Egypt; EGORD, Egyptian group of orphan renal diseases, 2, Elrasheed street, Mounira, 11617 Cairo, Egypt; Center of pediatric nephrology and transplantation, Cairo University, 2, Elrasheed street, Mounira, 11617 Cairo, Egypt.
Rasha
R
Helmy
Department of pediatrics, Kasr Al Ainy School of Medicine, Cairo University, 2, Elrasheed street, Mounira, 11617 Cairo, Egypt.
Khaled
K
Ghanim
Department of pediatrics, Kasr Al Ainy School of Medicine, Cairo University, 2, Elrasheed street, Mounira, 11617 Cairo, Egypt; EGORD, Egyptian group of orphan renal diseases, 2, Elrasheed street, Mounira, 11617 Cairo, Egypt; Center of pediatric nephrology and transplantation, Cairo University, 2, Elrasheed street, Mounira, 11617 Cairo, Egypt.
Hafez M
HM
Bazaraa
Department of pediatrics, Kasr Al Ainy School of Medicine, Cairo University, 2, Elrasheed street, Mounira, 11617 Cairo, Egypt; EGORD, Egyptian group of orphan renal diseases, 2, Elrasheed street, Mounira, 11617 Cairo, Egypt; Center of pediatric nephrology and transplantation, Cairo University, 2, Elrasheed street, Mounira, 11617 Cairo, Egypt.
Ahmed M
AM
Badr
Department of pediatrics, Kasr Al Ainy School of Medicine, Cairo University, 2, Elrasheed street, Mounira, 11617 Cairo, Egypt.
Omar A
OA
Tolba
Department of pediatrics, Kasr Al Ainy School of Medicine, Cairo University, 2, Elrasheed street, Mounira, 11617 Cairo, Egypt; Pediatric hepatology unit, Cairo University, 2, Elrasheed street, Mounira, 11617 Cairo, Egypt.
Magd A
MA
Kotb
Nephrology division, Military medical academy, 7, Ehsan abdelkodos street, Manshiet Elbakry, 11774 Cairo, Egypt.
Khaled M
KM
Eweeda
Department of general surgery, Ain Shams University, El-Khalifa El-Maamoun, Al Waili, 11588 Cairo, Egypt.
Alaa
A
Fayez
D000328:Adult; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003241:Consanguinity; D004534:Egypt; D005260:Female; D006801:Humans; D006960:Hyperoxaluria, Primary / Q000175:diagnosis* / Q000235:genetics* / Q000378:metabolism / Q000401:mortality; D007223:Infant; D007676:Kidney Failure, Chronic / Q000235:genetics; D008297:Male; D009154:Mutation; D009397:Nephrocalcinosis / Q000175:diagnosis / Q000235:genetics; D053040:Nephrolithiasis / Q000175:diagnosis / Q000235:genetics; D010641:Phenotype; D011736:Pyridoxine / Q000627:therapeutic use; D012189:Retrospective Studies; D012307:Risk Factors; D062606:Tertiary Care Centers; D000637:Transaminases / Q000235:genetics*; D016896:Treatment Outcome; D014803:Vitamin B Complex
D014803:Vitamin B Complex; D000637:Transaminases; C019635:Alanine-glyoxylate transaminase; D011736:Pyridoxine
End-stage renal disease; Nephrocalcinosis; Nephrolithiasis; Oxalosis; Post-transplantation recurrence; Primary hyperoxaluria type 1