Correlation of thyroid and growth hormones to chromosomal instability in Egyptian Fanconi anemia patients.

OBJECTIVE: Fanconi anemia (FA) is a rare inherited genomic instability syndrome and usually associated with endocrine dysfunctions. We aimed to assess the diagnostic standards of chromosomal instability in FA and to correlate the breakage frequency with the severity of endocrinal dysfunctions. METHODS: Twenty seven FA patients were randomly selected from Hematology Unit of Mansoura University Children's Hospital; their mean age 8.8 yr. Sixteen normal children matched for age and sex were used as controls. Cytogenetic studies included peripheral blood lymphocyte cultures using phytohemagglutinin to obtain chromosomal spreads. Chromosomal breakage was induced by (i) Diepoxybutane 0.1 mug/ml. (ii) Mitomycin C 0.1 microg/ml. (iii) Irradiation of cultures to four radiation doses; 75, 150, 300 and 400 rads (rad1, rad2, rad3 and rad4 respectively). Chromosomal aberrations were scored from the previous 6 cultures besides a culture for spontaneous chromosomal breakage; then mean chromosomal breakage was calculated for the seven cultures. Endocrinal evaluation included quantitative determination of thyroid stimulating hormone (TSH) and tetraiodothyronine (T4), serum growth hormone (GH), insulin like growth factor-1 (IGF-1) and insulin levels. RESULTS: Chromosomal breakage was found to be significantly higher in patients than control when induced by Diepoxybutane (p = 0.003), Mitomycin (p = 0.001), rad3 (p = 0.043) and rad4 (p = 0.001). Mean chromosomal breakage was significantly negative correlated to head circumference (r = -0.57) and GH level (r = -0.50), with no significant correlation to other hormonal parameters. Mitomycin and rad4 were found more accurate than DEB test for diagnosis of FA in suspected cases. CONCLUSION: Correction of the frequently associated hormonal dysfunction (reduced GH and T4) should be considered in the treatment discipline of FA patients to improve their final height.

NPHS2 mutations.

OBJECTIVE: To uncover the frequency and the spectrum of NPHS2 mutations in Egyptian children with non familial steroid-resistant nephrotic syndrome (SRNS). METHODS: Sixteen patients were screened by PCR-single-strand conformation polymorphism analysis of NPHS2 gene followed by direct sequencing. RESULTS: NPHS2 mutations were evident in four patients (25%) who were bearing four novel mutations including two frame shift mutations (R238fs and P45fs) and two missense mutations (I136L and F216Y). There were no phenotypic or histological characteristics of patients bearing NPHS2 mutations, apart from the earlier onset of the disease, compared to those who were not bearing mutations. CONCLUSION: NPHS2 mutations are prevalent in Egyptian children with non-familial SRNS and this may in part explain the less favorable prognosis reported in these patients.