Molecular analysis of SOX3 gene in patients with combined pituitary hormone deficiency (CPHD) by MLPA technique

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: SUN 624-646-Growth: Clinical Trials & Observational Studies
Clinical
Sunday, June 16, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board SUN-640
João Luiz de Oliveira Madeira*1, Marcela Moura Franca2, Aline Pedrosa Otto2, Fernanda de Azevedo Correa3, Mariana Funari1, Ivo J Arnhold4, Berenice Bilharinho Mendonca4 and Luciani Renata Silveira Carvalho5
1Hospital das Clínicas, University of São Paulo, Medical School, São Paulo, Brazil, 2Univ of Sao Paulo, Sao Paulo, Brazil, 3Hospital das Clinical - FMUSP, Sao Paulo- SP, Brazil, 4Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil, 5Hosp das Clinicas, Sao Paulo, Brazil
Background and Aims: Point mutations and small deletions in the transcription factors HESX1, GLI2, PROP1, POU1F1, LHX3, LHX4 and SOX2 are associated with hypopituitarism. Few reports of SOX3 gene duplications, deletions, and polyalanine tract expansions have been described in male and female patients with isolated GH deficiency (IGHD) or combined pituitary hormones deficiency (CPHD). We aimed to look for SOX3 deletions and duplications in patients with CPHD using MLPA. Patients: We selected 43 patients with CPHD (16 women), with age ranging from 1.6 to 32.7 years at diagnosis. Their initial height Z score ranged from -9.1 to -1.7 and 27 patients have ectopic posterior pituitary lobe; DNA from 24 Brazilian subjects (12 women) were used as controls. Methods: Four probes were designed according to the manufacturer's instructions (MRC Holland®) to cover the different regions of the gene. DNA samples were amplified and MLPA products were subjected to electrophoresis. The results were analyzed using the Peak Scanner® (Applied Biosystems®). Gene duplication was considered when dosage quotient (DQ) >1.3 and deletion when DQ<0.7. Experiments were considered appropriate when standard deviation of all probes of the reference runs was ≤0.1. Patients’ samples were compared to the same sex controls, since the SOX3 gene is X-linked. Results: All experiments were adequate showing reference runs of 0.02 to 0.05 SD in the male samples and of 0.02 to 0.06 SD in the female samples. Male patients had DQ from 0.72 to 1.30, similar to male controls (0.84 to 1.16) and female patients had DQ from 0.79 to 1.30, same range of female controls (0.84 to 1.18). Discussion: SOX3 gene deletions and duplications were not found in our cohort of CPHD patients. Although the MLPA technique is sensitive enough to detect deletions /duplications, it is not suitable to assess polyalanine tract expansions, therefore this analysis by PCR and sequencing is necessary. Conclusion: No deletions or duplications of SOX3 were detected in our series of 43 patients with CPHD, but it is necessary to expand the number of patients to analyze the real contribution of SOX3 defects in the etiology of CPHD.

Nothing to Disclose: JLDOM, MMF, APO, FDAC, MF, IJA, BBM, LRSC

*Please take note of The Endocrine Society's News Embargo Policy at http://www.endo-society.org/endo2013/media.cfm

Sources of Research Support: Fundação de Amparo à pesquisa do Estado de São Paulo - FAPESP