scholarly journals Novel Mutations within the POU1F1 Gene Associated with Variable Combined Pituitary Hormone Deficiency

2005 ◽  
Vol 90 (8) ◽  
pp. 4762-4770 ◽  
Author(s):  
James P. G. Turton ◽  
Rachel Reynaud ◽  
Ameeta Mehta ◽  
John Torpiano ◽  
Alexandru Saveanu ◽  
...  
Keyword(s):  
Dna Binding ◽  
Mutational Analysis ◽  
Hot Spot ◽  
Dominant Negative ◽  
Hormone Deficiency ◽  
Pituitary Hormone ◽  
Novel Mutations ◽  
Pituitary Hormone Deficiency ◽  
Combined Pituitary Hormone Deficiency ◽  
Functional Studies

Context: Mutations within the gene encoding the pituitary-specific transcription factor POU1F1 are associated with combined pituitary hormone deficiency (CPHD). Most of the affected individuals manifest GH, prolactin, and TSH deficiency. Objective: We have now screened 129 individuals with CPHD and isolated GH deficiency for mutations within POU1F1. Results: Causative mutations were identified in 10 of 129 individuals (7.8%). Of these, five patients harbored the dominant negative R271W mutation, which is a well-recognized mutational hot spot. We have also identified a second frequently occurring mutation, E230K, which appears to be common in Maltese patients. Additionally, we describe two novel mutations within POU1F1, an insertion of a single base pair (ins778A) and a missense mutation (R172Q). Functional studies have revealed that POU1F1 (E230K) is associated with a reduction in transactivation, although DNA-binding affinity is similar to the wild-type protein. On the other hand, POU1F1 (R172Q) is associated with a reduction in DNA binding and transactivation, whereas POU1F1 (ins778A) is associated with loss of DNA binding and a reduction in transactivation. Conclusions: Our data suggest that the phenotype associated with POU1F1 mutations may be more variable, with the occasional preservation of TSH secretion. Additionally, our data revealed POU1F1 mutations in three patients who were diagnosed as having ACTH deficiency but who, on further evaluation, were found to have normal cortisol secretion. Hence, elucidation of the genotype led to further evaluation of the phenotype, with the cessation of cortisol replacement that had been commenced unnecessarily. These data reflect the importance of mutational analysis in patients with CPHD.

scholarly journals Combined Pituitary Hormone Deficiency Caused by Compound Heterozygosity for Two Novel Mutations in the POU Domain of the PIT1/POU1F1 Gene1

2001 ◽  
Vol 86 (4) ◽  
pp. 1545-1550 ◽  
Author(s):  
Brenda I. Hendriks-Stegeman ◽  
Kevin D. Augustijn ◽  
Bert Bakker ◽  
Pieternella Holthuizen ◽  
Peter C. van der Vliet ◽  
...  
Keyword(s):  
Hormone Deficiency ◽  
Pituitary Hormone ◽  
Compound Heterozygosity ◽  
Novel Mutations ◽  
Pituitary Hormone Deficiency ◽  
Combined Pituitary Hormone Deficiency ◽  
Pou Domain

scholarly journals OTX2 Loss of Function Mutation Causes Anophthalmia and Combined Pituitary Hormone Deficiency with a Small Anterior and Ectopic Posterior Pituitary

2009 ◽  
Vol 94 (1) ◽  
pp. 314-319 ◽  
Author(s):  
Toshihiro Tajima ◽  
Akira Ohtake ◽  
Masaya Hoshino ◽  
Shin Amemiya ◽  
Nozomu Sasaki ◽  
...  
Keyword(s):  
Brain Magnetic Resonance Imaging ◽  
Dominant Negative ◽  
Hormone Deficiency ◽  
Dominant Negative Effect ◽  
Pituitary Hormone ◽  
Posterior Lobe ◽  
Loss Of Function ◽  
Pituitary Hormone Deficiency ◽  
Combined Pituitary Hormone Deficiency ◽  
Negative Effect

Abstract Context: Orthodenticle homeobox 2 (OTX2) is a transcription factor necessary for ocular and forebrain development. In humans, heterozygous mutations of OTX2 cause severe ocular malformations. However, whether mutations of OTX2 cause pituitary structural abnormalities or combined pituitary hormone deficiency (CPHD) has not been clarified. Objectives: We surveyed the functional consequences of a novel OTX2 mutation that was detected in a patient with anophthalmia and CPHD. Patient: We examined a Japanese patient with growth disturbance, anophthalamia, and severe developmental delay. He showed deficiencies in GH, TSH, LH, FSH, and ACTH. Brain magnetic resonance imaging revealed a small anterior pituitary gland, invisible stalk, ectopic posterior lobe, and Chiari malformation. Results: Sequence analysis of OTX2 demonstrated a heterozygous two bases insertion [S136fsX178 (c.576-577insCT)] in exon 3. The mutant Otx2 protein localized to the nucleus, but did not activate the promoter of the HESX1 and POU1F1 gene, indicating a loss of function mutation. No dominant negative effect in the presence of wild-type Otx2 was observed. Conclusion: This case indicates that the OTX2 mutation is a cause of CPHD. Further study of more patients with OTX2 defects is necessary to clarify the clinical phenotypes and endocrine defects caused by OTX2 mutations.

scholarly journals Three Novel Missense Mutations within the LHX4 Gene Are Associated with Variable Pituitary Hormone Deficiencies

2008 ◽  
Vol 93 (3) ◽  
pp. 1062-1071 ◽  
Author(s):  
Roland W. Pfaeffle ◽  
Chad S. Hunter ◽  
Jesse J. Savage ◽  
Mario Duran-Prado ◽  
Rachel D. Mullen ◽  
...  
Keyword(s):  
Dna Binding ◽  
Gh Deficiency ◽  
Gene Activation ◽  
Nervous System Development ◽  
Hormone Deficiency ◽  
Pituitary Hormone ◽  
Gene Promoters ◽  
Missense Mutations ◽  
Pituitary Hormone Deficiency ◽  
Combined Pituitary Hormone Deficiency

Abstract Context: The LHX4 LIM-homeodomain transcription factor has essential roles in pituitary gland and nervous system development. Heterozygous mutations in LHX4 are associated with combined pituitary hormone deficiency. Objectives: Our objectives were to determine the nature and frequency of LHX4 mutations in patients with pituitary hormone deficiency and to examine the functional outcomes of observed mutations. Design: The LHX4 gene sequence was determined from patient DNA. The biochemical and gene regulatory properties of aberrant LHX4 proteins were characterized using structural predictions, pituitary gene transcription assays, and DNA binding experiments. Patients: A total of 253 patients from 245 pedigrees with GH deficiency and deficiency of at least one additional pituitary hormone was included in the study. Results: In five patients, three types of heterozygous missense mutations in LHX4 that result in substitution of conserved amino acids were identified. One substitution is between the LIM domains (R84C); the others are in the homeodomain (L190R; A210P). The patients have GH deficiency; some also display reductions in TSH, LH, FSH, or ACTH, and aberrant pituitary morphology. Structural models predict that the aberrant L190R and A210P LHX4 proteins would have impaired DNA binding and gene activation properties. Consistent with these models, EMSAs and transfection experiments using pituitary gene promoters demonstrate that whereas the R84C form has reduced activity, the L190R and A210P proteins are inactive. Conclusions: LHX4 mutations are a relatively rare cause of combined pituitary hormone deficiency. This report extends the range of phenotypes associated with LHX4 gene mutations and describes three novel exonic mutations in the gene.

scholarly journals Genetic background of inherited multiple pituitary hormone deficiency. Mutations of PROP1 gene in Hungary

2011 ◽  
Vol 152 (6) ◽  
pp. 221-232
Author(s):  
Zita Halász
Keyword(s):  
Growth Hormone ◽  
Growth Hormone Deficiency ◽  
Mutational Analysis ◽  
Hot Spot ◽  
Gene Mutations ◽  
Hormone Deficiency ◽  
Pituitary Hormone ◽  
Multiple Pituitary Hormone Deficiency ◽  
Pituitary Hormone Deficiency ◽  
Prop1 Gene

In this work I analysed the outcome of growth hormone replacement treatment in patients with inherited form of multiple pituitary hormone deficiency and examined diseased-causing mutations of pituitary transcription factor genes which may underlie this disorder. The results showed that after treatment for a longer than 7-year period with a growth hormone preparation available under well-controlled distribution, the mean height of children with growth hormone deficiency reached the normal national reference range adjusted for age and sex. After establishment of clinical criteria for screening PROP1 gene mutations, I performed mutational analysis of all coding exons of this gene in 35 patients with inherited form of multiple pituitary hormone deficiency. With these studies, diseases-causing PROP1 gene mutations were detected in 15 of the 35 patients (43%). It was also found that more than 80% of mutant alleles were accounted for by those containing the 150delA and 301-302delGA mutations of the PROP1 gene. Importantly, these findings indicated a high relevance of mutational ”hot spots” of the PROP1 gene in Hungarian patients with inherited form of multiple pituitary hormone deficiency and they also offered an opportunity for the development of rational and cost-effective screening strategy. When clinical and hormonal findings of patients with and without PROP1 gene mutations were compared, results showed that growth hormone deficiency was diagnosed at earlier age of life in patients with PROP1 gene mutations, but the severity of growth retardation at the time of diagnosis of growth hormone deficiency or the age of patients at the time of manifestation of other pituitary hormone deficiencies (TSH, LH, FSH and ACTH) were similar in the two groups of patients. In 15 patients inherited form of multiple pituitary hormone deficiency who had no PROP1 gene mutations, exon 6 of the POU1F1 gene containing a mutational ”hot spot” was also examined but no mutations were found. Thus, these results do not support a significant role of the mutational ”hot spot” of the POU1F1 gene in Hungarian patients with inherited form of multiple pituitary hormone deficiency. Finally, I introduced a method for the detection of mutations of the PITX2 gene, a pituitary transcription factor that plays a role not only in pituitary development and differentiation but also in the lateralization of organs. With the use of this method, I performed mutational analysis of all coding exons of this gene in an exceptionally unique patient who had both situs inversus totalis and inherited form of multiple pituitary hormone deficiency, but no mutation was found. Thus, the findings in this patient failed to indicate that mutation of the PITX2 gene is involved in the pathomechanism of situs inversus totalis associated with inherited form of multiple pituitary hormone deficiency. Orv. Hetil., 2011, 152, 221–232.

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