Novel and recurrent mutations in the TAT gene in Tunisian families affected with Richner-Hanhart syndrome.

Tyrosinemia type II, also designated as oculocutaneous tyrosinemia or Richner-Hanhart syndrome (RHS), is a very rare autosomal recessive disorder. In the present study, we report clinical features and molecular genetic investigation of the tyrosine aminotransferase (TAT) gene in two young patients, both born to consanguineous unions between first-degree cousins. These two unrelated families originated from Northern and Southern Tunisia. The clinical diagnosis was based on the observation of several complications related to Richner-Hanhart syndrome: recurrent eye redness, tearing and burning pain, photophobia, bilateral pseudodendritic keratitis, an erythematous and painful focal palmo-plantar hyperkeratosis and a mild delay of mental development. The diagnosis was confirmed by biochemical analysis. Sequencing of the TAT gene revealed the presence of a previously reported missense mutation (c.452G>A, p.Cys151Tyr) in a Tunisian family, and a novel G duplication (c.869dupG, p.Trp291Leufs 6). Early diagnosis of RHS and protein-restricted diet are crucial to reduce the risk and the severity of long-term complications of hypertyrosinemia such as intellectual disability.

Celiac disease in Tunisian children: a second screening study using a "new generation" rapid test.

This work aims to estimate celiac disease prevalence in school-children in the island of Djerba and assess rapid method feasibility for screening. We screened 2064 schoolchildren by a rapid method to detect IgA anti-tissue transglutaminase and IgA deficiency. Children with positive results were tested for IgA anti-transglutaminase and anti-endomysium by conventional tests. In positive children, intestinal biopsy was performed. IgA deficiency suspected by rapid method was confirmed by nephelometry. In these cases IgG anti-endomysium was performed. Rapid test was positive in 7 children; conventional serology was positive in all and 6 of them accepted the biopsy. Total villous atrophy was observed in 5 while intestinal mucosa was normal in one. Among children with positive serology, 3 had silent form, 1 chronic diarrhea, one growth failure and 2 had borderline growth. IgA deficiency was suspected in 13 cases and was confirmed in 11 children tested. Prevalence of celiac disease was 0.24-0.34% and that of IgA deficiency 0.5-0.6%. This screening study confirms that celiac disease is relatively common in schoolchildren in Tunisia. It confirms also that even those with symptoms typical for celiac disease escape diagnosis. Rapid test is better accepted by parents and children than test requiring a venous blood sample.