RESUMO
In the present study we report the clinical features and the molecular genetic investigation of the tyrosine aminotransferase (TAT) gene in a young girl from Croatia with Richner-Hanhart syndrome, mainly suffering from photophobia, hyperkeratosis of the palmes and soles and slight neurological abnormalities. Sequencing analysis of the TAT gene revealed a novel homozygous missense mutation c.1250G>A (p.R417Q) in exon 12, and herewith confirmed the clinical diagnosis. Showing the first symptoms in babyhood, at the age of 8 years it was for the first time clinically diagnosed that the patient suffers from tyrosinemia type II and a therapy with tyrosine and phenylalanine reduced diet has been started successfully. All symptoms disappeared within 2-4 weeks. Since that time, we have been following the girl until today for more than ten years. She is in a good condition, and attends the normal high school program.
Assuntos
Doenças da Córnea/genética , Ceratodermia Palmar e Plantar/genética , Mutação de Sentido Incorreto , Tirosina Transaminase/genética , Tirosinemias/genética , Sequência de Bases , Doenças da Córnea/enzimologia , Doenças da Córnea/patologia , Análise Mutacional de DNA , Feminino , Humanos , Ceratodermia Palmar e Plantar/enzimologia , Ceratodermia Palmar e Plantar/patologia , Síndrome , Tirosina Transaminase/deficiência , Tirosinemias/enzimologia , Tirosinemias/patologia , Adulto JovemAssuntos
Ferroquelatase/genética , Ceratodermia Palmar e Plantar/genética , Mutação/genética , Protoporfiria Eritropoética/genética , Consanguinidade , Análise Mutacional de DNA , Homozigoto , Humanos , Ceratodermia Palmar e Plantar/complicações , Ceratodermia Palmar e Plantar/enzimologia , Masculino , Pessoa de Meia-Idade , Linhagem , Protoporfiria Eritropoética/complicações , Protoporfiria Eritropoética/enzimologiaRESUMO
Estrone (E1)-sulfatase and dehydroepiandrosterone (DHEA)-sulfatase activities were studied in human female epidermis. Skin specimens were obtained by abdominal or plantar biopsies. The apparent Michaelis-Menten constants for E1 and DHEA sulfatases were 35.2 microM and 8.7 microM, respectively. A substrate inhibition was only observed for DHEA sulfatase. Both sulfatases had an elevated temperature optimum (65 degrees C). The effect of inorganic salts was also tested. In normal epidermis, E1-sulfatase activity was constantly higher than DHEA-sulfatase activity, but no correlation between these activities was observed. On the other hand, E1- and DHEA-sulfatase activities were lower in plantar than in abdominal epidermis. In plantar epidermis of palmoplantar keratoderma, large variations in E1-sulfatase activity, but no significant variation in DHEA-sulfatase activity, were observed. In human epidermis, the findings were consistent with the existence of two different sulfatases: E1 sulfatase and DHEA sulfatase. It would also appear that sulfatase activities are not linked to the abnormal shedding of plantar stratum corneum in palmoplantar keratoderma.
Assuntos
Epiderme/enzimologia , Sulfatases/metabolismo , Abdome , Eczema/enzimologia , Feminino , Humanos , Ceratodermia Palmar e Plantar/enzimologia , Menopausa , Esteril-Sulfatase , Fatores de TempoRESUMO
A middle-aged adult male with a mild form of tyrosinemia II (Richner-Hanhart syndrome) is described. Treatment with a low-tyrosine diet caused a fall in plasma tyrosine and clearing of the hyperkeratosis of the soles. Liver biopsy of this patient revealed low but measurable levels of cytoplasmic tyrosine aminotransferase and elevated levels of the mitochondrial tyrosine-metabolizing enzyme aspartate aminotransferase. It is hypothesized that these enzymes have been induced in sufficient amounts to account for the mild clinical course.
