Ochronotic rheumatism in Algeria: clinical, radiological, biological and molecular studies--a case study of 14 patients in 11 families.
OBJECTIVE
To confirm alkaptonuria and ochronotic arthropathy diagnosis by mutation screening of the homogentisate 1,2-dioxygenase (HGD) gene. Try to establish a genotype-phenotype correlation in the five subjects with a molecular study on HGD gene.


METHODS
We report 14 alkaptonuria cases (10 men and four women) in 11 Algerian families. Consanguineous matings were evidenced in only three families (F = 1/16). Molecular analysis was performed by sequencing genomic DNA in order to identify the mutations of the HGD gene.


RESULTS
Alkaptonuria was always confirmed by urinary homogentisic acid determination. Four different mutations of the HGD gene were found: an homozygous missense mutation, Serine189Isoleucine in two sisters with a mild phenotype; an homozygous splice site mutation (IVS1-1G > A) in a man with a severe phenotype (death at 61 years old from renal failure); a silent mutation, Alanine470Alanine at the heterozygous state in a man with a mild phenotype; a 'G' deletion at the position c.819 which causes a frameshift after Gly217(Gly217fs) that runs into a stop codon at c. 850. This mutation is novel and was found in heterozygosis in a woman with a mild phenotype.


CONCLUSIONS
The two homozygous mutations were associated, respectively, with a severe and a mild phenotype but no genotype-phenotype correlation could be found.
Ladjouze-Rezig
Aicha
A
Rheumatology Department, Ben Aknoun Hospital, Algiers, Algeria. robert.aquaron@medecine.univ-mrs.fr
Rodriguez de Cordoba
Santiago
S
Aquaron
Robert
R
D000293:Adolescent; D000328:Adult; D000368:Aged; D000474:Alkaptonuria / Q000175:diagnosis / Q000235:genetics* / Q000473:pathology*; D004247:DNA / Q000032:analysis / Q000235:genetics; D005260:Female; D005820:Genetic Testing; D005838:Genotype; D050560:Homogentisate 1,2-Dioxygenase / Q000235:genetics; D006720:Homozygote; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010641:Phenotype; D012216:Rheumatic Diseases / Q000175:diagnosis / Q000235:genetics* / Q000473:pathology*
D004247:DNA; D050560:Homogentisate 1,2-Dioxygenase