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1.
Am J Med Genet A ; 194(7): e63603, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38511620

ABSTRACT

There is an emerging body of evidence showing that young patients, post haematopoietic stem cell transplantation (HSCT), can develop skeletal changes that mimic an osteochondrodysplasia process. The key discriminator is that these children have had otherwise normal growth and skeletal development before the therapeutic intervention (HSCT), typically for a haematological malignancy. Herein we present that case of a boy who underwent HSCT for Haemophagocytic Lymphohistiocytosis (HLH) aged 2 years. Following Intervention with HSCT this boy's growth has severely decelerated (stature less than 1st centile matched for age) and he has developed a spondyloepiphyseal dysplasia.


Subject(s)
Hematopoietic Stem Cell Transplantation , Lymphohistiocytosis, Hemophagocytic , Osteochondrodysplasias , Humans , Hematopoietic Stem Cell Transplantation/adverse effects , Male , Osteochondrodysplasias/genetics , Osteochondrodysplasias/pathology , Child, Preschool , Lymphohistiocytosis, Hemophagocytic/genetics , Lymphohistiocytosis, Hemophagocytic/pathology , Lymphohistiocytosis, Hemophagocytic/etiology , Growth Disorders/pathology , Growth Disorders/etiology , Growth Disorders/genetics
3.
Orphanet J Rare Dis ; 17(1): 162, 2022 04 11.
Article in English | MEDLINE | ID: mdl-35410222

ABSTRACT

BACKGROUND: Rare diseases (RDs) are often complex, serious, chronic and multi-systemic conditions, associated with physical, sensory and intellectual disability. Patients require follow-up management from multiple medical specialists and health and social care professionals involving a high level of integrated care, service coordination and specified care pathways. METHODS AND OBJECTIVES: This pilot study aimed to explore the best approach for developing national RD care pathways in the Irish healthcare system in the context of a lack of agreed methodology. Irish clinical specialists and patient/lived experience experts were asked to map existing practice against evidence-based clinical practice guidelines (CPGs) and best practice recommendations from the European Reference Networks (ERNs) to develop optimal care pathways. The study focused on the more prevalent, multisystemic rare conditions that require multidisciplinary care, services, supports and therapeutic interventions. RESULTS: 29 rare conditions were selected across 18 ERNs, for care pathway development. Multidisciplinary input from multiple specialisms was relevant for all pathways. A high level of engagement was experienced from clinical leads and patient organisations. CPGs were identified for 26 of the conditions. Nurse specialist, Psychology, Medical Social Work and Database Manager roles were deemed essential for all care pathways. Access to the therapeutic Health Service Professionals: Physiotherapy, Occupational Therapy, and Speech and Language Therapy were seen as key requirements for holistic care. Genetic counselling was highlighted as a core discipline in 27 pathways demonstrating the importance of access to Clinical Genetics services for many people with RDs. CONCLUSIONS: This study proposes a methodology for Irish RD care pathway development, in collaboration with patient/service user advocates. Common RD patient needs and health care professional interventions across all pathways were identified. Key RD stakeholders have endorsed this national care pathway initiative. Future research focused on the implementation of such care pathways is a priority.


Subject(s)
Critical Pathways , Rare Diseases , Delivery of Health Care , Humans , Ireland , Pilot Projects , Rare Diseases/therapy
4.
Ir Med J ; 112(9): 999, 2019 10 15.
Article in English | MEDLINE | ID: mdl-31651129

ABSTRACT

Aim Our aim was to design a new insulin prescribing tool in compliance with the Irish Medicines Safety Network recommendations. Methods In 2015, we undertook a review of the existing paediatric subcutaneous insulin-prescribing sheet introduced to Cork University Hospital in 2013. This involved a retrospective analysis of 15 consecutive in-patient insulin prescribing charts and a questionnaire distributed to health professionals. Following this a new insulin prescribing chart was designed and implemented in 2016 and a re-audit was performed in 2017. Results The 2017 re-audit demonstrated that the new insulin chart was viewed as easier (95% of previous users n=18) and safer (n=16) to use. There was less confusion (2017: 28%, n=11/39 vs 2015: 50%, n=17/34 2015) and the ALERT system helped staff standardise hypo/hyperglycaemia management (71%, n=28). Conclusion The new paediatric insulin prescribing chart has improved safety and ease of prescribing insulin. The colour coded quasi graph and ALERT system has made it easier to appreciate capillary blood glucose trends and manage them safely.


Subject(s)
Diabetes Mellitus/drug therapy , Insulin/administration & dosage , Prescriptions/statistics & numerical data , Child , Humans , Patient Safety , Retrospective Studies
5.
Ir Med J ; 112(3): 898, 2019 03 14.
Article in English | MEDLINE | ID: mdl-31124347

ABSTRACT

Aims To analyse all paediatric patients who presented with diabetic ketoacidosis (DKA) from 2012 to 2017. Methods A retrospective observational study was carried out analysing all cases of diabetic ketoacidosis admitted to a regional centre from 2012-2017. Results We identified 133 cases of DKA, 81 (61%) were newly diagnosed patients and 52 (39%) were patients with known T1DM. There were 215 new diagnoses of T1DM during the study period giving a DKA rate at diagnosis of 38%. Among the 52 cases with established T1DM, 13 cases (25%) presented in severe DKA and 37 cases (71%) occurred in adolescents aged over 12 years. Precipitating factors included chronic suboptimal control and psychosocial factors (28/52), acute illness (16/52), and pump technical failure (5/52). There were two cases treated for suspected cerebral oedema and one case each of subarachnoid haemorrhage and cardiac arrhythmia. Conclusion The current proportion of new T1DM presenting in DKA is higher than international data. The high frequency of DKA in known T1DM indicates a need for particular focus on adolescents.


Subject(s)
Diabetes Mellitus, Type 1/complications , Diabetes Mellitus, Type 1/epidemiology , Diabetic Ketoacidosis/epidemiology , Diabetic Ketoacidosis/etiology , Adolescent , Child , Child, Preschool , Female , Humans , Incidence , Infant , Infant, Newborn , Ireland/epidemiology , Male , Retrospective Studies , Time Factors
6.
J Wound Care ; 26(Sup10): S20-S28, 2017 Oct 01.
Article in English | MEDLINE | ID: mdl-28976830

ABSTRACT

Care of the patient with a presumed life- or limb-threatening lower extremity wound poses many challenges. The mindset regarding potential outcomes of such conditions is mostly driven by the experiences and expertise of those providing the care. This mindset generally appears as two primary actions presented to the afflicted patient: attempted resolution of the problem via medical, surgical or combination treatment, with the hope of low recurrence risk, or exacerbation and amputation-amputations at a level sufficient to, at least in the mind of the surgeon, eliminate the problem. Achieving the former outcome is dependent on a number of factors associated with both patient and caregiver. If healing is achieved, the secondary goal of prevention of recurrence may be no less arduous, with failure most likely resulting in amputation. Clearly, these considerations appear to be based more on the health professionals perception, of the patient's physical and medical status rather than on patient-centred considerations. This article will review considerations and recommendations for lower extremity amputation, and the short- and long-term implications. Based on our research, there is clear need for a set of criteria against which to weigh not just the medical issues, but also definitive patient-centred issues when considering a lower extremity amputation. We offer a set of patient-centred, easily verified and recognised criteria that we believe addresses this need. The goal of the Miller-Newgent Amputation Scale (MENACE) is to provide a decision base from which to consider and evaluate all factors in determining the need for a lower extremity amputation. This involves identification of patient-centred issues, which are likely to produce satisfactory short- and long-term physical and quality-of-life outcomes if the amputation does proceed.


Subject(s)
Leg Injuries/surgery , Severity of Illness Index , Amputation, Surgical , Decision Support Techniques , Humans , Limb Salvage , Patient-Centered Care , Risk Factors , Wound Healing
7.
Diabet Med ; 34(11): 1603-1607, 2017 11.
Article in English | MEDLINE | ID: mdl-28703902

ABSTRACT

OBJECTIVE: To establish the prevalence of paediatric Type 2 diabetes in the Republic of Ireland and describe patient demographics, initial presentation, management, outcomes, comorbidities and complications. METHODS: Using a standardized proforma we conducted a cross-sectional survey of children and adolescents aged < 16 years with a diagnosis of Type 2 diabetes between October and December 2015 in each of the 19 centres in the Republic of Ireland responsible for the care of children with diabetes. RESULTS: Twelve cases of Type 2 diabetes were identified, giving a prevalence in children aged <16 years of 1.2/100 000 (95% CI 0.6 to 2). Six of these children (50%) were white, two (33%) of whom were members of the travelling community. Four (33%) were of black ethnicity. The prevalence of Type 2 diabetes in traveller children was 16.1/100 000 (95% CI 1.9 to 58.1) and was similar to that in black children, a known high-risk group, which was 13.3/100 000 (95% CI 3.6 to 34.1). The median current HbA1c value was 51 mmol/mol (6.8%) and four (33%) of the children achieved the International Society for Pediatric and Adolescent Diabetes target HbA1c of ≤48 mmol/mol (6.5%). Seven (59%) children were managed on metformin monotherapy, three (25%) were managed on insulin and metformin in combination, and two (16%) were receiving dietary management. CONCLUSION: This was the first national study to estimate the prevalence of childhood Type 2 diabetes in Ireland. Despite their white ethnicity, traveller children appear to be a high-risk group, but this finding requires further study.


Subject(s)
Diabetes Mellitus, Type 2/drug therapy , Diabetes Mellitus, Type 2/epidemiology , Hypoglycemic Agents/therapeutic use , Adolescent , Child , Child, Preschool , Cross-Sectional Studies , Female , Humans , Infant , Insulin/therapeutic use , Ireland/epidemiology , Male , Metformin/therapeutic use , Prevalence
9.
Ir Med J ; 109(2): 356, 2016 Feb 19.
Article in English | MEDLINE | ID: mdl-27685690

ABSTRACT

Many countries have established regulations regarding growth hormone (GH) treatment in children, to standardise care and reduce cost. In this study, we describe current practice in Ireland surrounding child measurement and the approach to diagnosis of GH deficiency. A questionnaire was sent to 139 paediatricians in Ireland and 35 (9 paediatric endocrinologists) responded. Only 13 (37.1%) use the recommended 2-person technique for measuring children under 2. Amongst GH prescribers, there were a variety of GH Stimulation Tests used, sex steroid priming was used by 8 (80%) and the general cut off for a passed test was consistent (7ng/ml). Brand rotation (n=5, 50%) and cost (n=3, 30%) were the most common criteria for deciding the formulation of GH prescribed. We recommend that departments review their child measurement technique and equipment. We also advise the establishment of national guidelines for the use of GH, and a prospective registry for GH treated children.

10.
Ir Med J ; 103(9): 275-8, 2010 Oct.
Article in English | MEDLINE | ID: mdl-21186752

ABSTRACT

We sought to evaluate the oral health status of children born small for gestational age (SGA). Children now aged 4-8 years who were born SGA (birth weight < -2 SDS) were examined using standardised criteria. The parents completed a structured oral health questionnaire. Twenty females and 25 males, mean age 72.1 months, and mean birth weight 2.1 kg, participated in the study. Poor appetite was a concern; 32 (71%) children snacked between meals and 14 (30%) used carbonated beverages more than 3 times daily. Erosion was present in 9 (20%) children. Dental decay occurred in 22 (47%) children with 92% being untreated. Eight children had more than 5 decayed teeth. It is essential that clinicians working with children born SGA include oral health within the general health surveillance and refer these children for a dental assessment within the first 2 years to support parents in establishing safe feeding patterns for their children.


Subject(s)
Infant, Small for Gestational Age , Oral Health , Child , Child, Preschool , Dental Caries/epidemiology , Female , Follow-Up Studies , Humans , Infant, Newborn , Male , Tooth Erosion/epidemiology
11.
Open Dent J ; 3: 92-9, 2009 May 20.
Article in English | MEDLINE | ID: mdl-19543550

ABSTRACT

BACKGROUND: The healing potential of platelet growth factors has generated interest in using Platelet-Rich Plasma (PRP) in ridge preservation procedures. A canine study was performed to determine if extraction sites treated with platelet-rich fibrin matrix (PRFM) exhibit enhanced healing compared to sites treated with non-viable materials. METHODS: Four dog's extraction sockets were treated individually with PRFM, PRFM and membrane, Demineralized Freeze-Dried Bone Allograft (DFDBA) and membrane, PRFM and DFDBA, and untreated control. Treatment sequencing permitted clinical and histologic evaluation of healing at 10 days, 2, 3, 6 and 12 weeks. RESULTS: Healing was more rapid in the PRFM and PRFM and membrane sites. By 3 weeks those sockets had osseous fill. Sites containing DFDBA had little new bone at 6 weeks. By 12 weeks those sockets had osseous fill but DFDBA particles were still noted in coronal areas. CONCLUSIONS: PRFM alone may be the best graft for ridge preservation procedures. ADVANTAGES: faster healing, and elimination of disadvantages involved in using barrier membranes.

12.
J Vector Ecol ; 27(1): 86-95, 2002 Jun.
Article in English | MEDLINE | ID: mdl-12125878

ABSTRACT

The superior larval competitive ability of Aedes albopictus has been proposed to explain the recent displacement of Aedes aegyptiby the former species inparts of the southeastern U.S. Ae. aegypti persists, however, in sympatry with Ae. albopictus in urban areas of southern Louisiana, Florida, and Texas, and the impact of larval competition between these species has not been investigated at higher temperatures that may be characteristic of these urban environments. We compared growth and survivorship of the two species at controlled temperatures of 24 degrees and 30 degrees C in water-containing tires under conditions of intra- and interspecific competition and with or without leaf litter. When other variables were controlled statistically, the estimated finite rate of increase (lambda') was significantly higher for both species at the higher temperature, and the proportional increases in lambda' did not differ between species. Therefore, our experiment predicts that by itself, temperatures between 24 degrees and 30 degrees C would not alter the outcome of larval competition. Overall, response measures of Ae. albopictus were more sensitive than those of Ae. aegypti to the litter and species/density variables, although the development ofAe. aegypti females was uniquely retarded by a high density of its own species.


Subject(s)
Adaptation, Physiological , Aedes , Temperature , Animals , Larva/growth & development , Plant Leaves , Population Dynamics , Survival , Water
13.
Recent Prog Horm Res ; 55: 1-13; discussion 13-4, 2000.
Article in English | MEDLINE | ID: mdl-11036930

ABSTRACT

During development of the mammalian pituitary gland, specific hormone-producing cell types, critical in maintaining homeostasis, emerge in a spatially and temporally specific fashion from an ectodermal primordium. We have investigated the molecular basis of generating diverse cell phenotypes from a common precursor, providing in vivo and in vitro evidence that development of these cell types involves at least four sequential phases of signaling events and the action of a gradient at an ectodermal boundary. In the first phase, we hypothesize that this notochord induces invagination of Rathke's pouch from the oral ectoderm. This is followed by appearance of an ectodermal boundary, formed with exclusion of Shh from the nascent pouch. Next, signals from the ventral diencephalon--expressing BMP4, Wnt5a, FGF10, and FGF8--in concert with Shh represent critical in vivo signals for pituitary determination. Subsequently, a dorsal-ventral BMP2 signal gradient emanates from a ventral pituitary organizing center, forming at the boundary to oral ectoderm region from which Shh expression is selectively excluded. In concert with a dorsal FGF8 signal, this creates opposing gradients that generate overlapping patterns of specific transcription factors that underlie cell lineage specification events. The mechanisms by which these transient gradients of signaling molecules lead to the appearance of four ventral pituitary cell types appear to involve the reciprocal interactions of two transcription factors, Pit-1 and GATA-2, which are epistatic to the remainder of the cell type-specific transcription programs and serve as a molecular memory of the transient signaling events. Unexpectedly, this program includes a DNA-binding-independent function of Pit-1, suppressing the ventral GATA-2-dependent gonadotrope program by inhibiting GATA-2 binding to gonadotrope- but not thyrotrope-specific genes. This indicates that both DNA-binding-dependent and-independent actions of abundant determining factors contribute to generate distinct cell phenotypes. In the fourth phase, temporally specific loss of the BMP2 signal is required to allow terminal differentiation. The consequence of these sequential organ and cellular determination events is that each of the pituitary cell types--gonadotropes, thyrotropes, somatotropes, lactotropes, corticotropes, and melanotropes appears to be determined, in a ventral to dorsal gradient, respectively, apparently based on a combinatorial code of transcription factors induced by the gradient of specific signaling molecules.


Subject(s)
Pituitary Gland/embryology , Transforming Growth Factor beta , Animals , Bone Morphogenetic Protein 2 , Bone Morphogenetic Proteins/metabolism , DNA-Binding Proteins/metabolism , Fibroblast Growth Factor 8 , Fibroblast Growth Factors/metabolism , GATA2 Transcription Factor , Mice , Pituitary Gland/cytology , Pituitary Gland/metabolism , Signal Transduction , Transcription Factor Pit-1 , Transcription Factors/metabolism , Transcription, Genetic
14.
Neuron ; 28(3): 779-92, 2000 Dec.
Article in English | MEDLINE | ID: mdl-11163266

ABSTRACT

Axon pathfinding relies on the ability of the growth cone to detect and interpret guidance cues and to modulate cytoskeletal changes in response to these signals. We report that the murine POU domain transcription factor Brn-3.2 regulates pathfinding in retinal ganglion cell (RGC) axons at multiple points along their pathways and the establishment of topographic order in the superior colliculus. Using representational difference analysis, we identified Brn-3.2 gene targets likely to act on axon guidance at the levels of transcription, cell-cell interaction, and signal transduction, including the actin-binding LIM domain protein abLIM. We present evidence that abLIM plays a crucial role in RGC axon pathfinding, sharing functional similarity with its C. elegans homolog, UNC-115. Our findings provide insights into a Brn-3.2-directed hierarchical program linking signaling events to cytoskeletal changes required for axon pathfinding.


Subject(s)
Axons/metabolism , DNA-Binding Proteins/metabolism , Homeodomain Proteins , Transcription Factors/metabolism , Visual Pathways/embryology , Visual Pathways/metabolism , Animals , Axons/ultrastructure , Cell Communication/genetics , Chick Embryo , DNA-Binding Proteins/genetics , DNA-Binding Proteins/pharmacology , Gene Expression Profiling/methods , Growth Cones/metabolism , LIM Domain Proteins , Mice , Mice, Knockout , Microfilament Proteins/genetics , Microfilament Proteins/metabolism , Molecular Sequence Data , Optic Nerve/pathology , Optic Nerve Diseases/genetics , Optic Nerve Diseases/pathology , Protein Structure, Tertiary , Retina/pathology , Retinal Ganglion Cells/cytology , Retinal Ganglion Cells/metabolism , Sequence Homology, Amino Acid , Signal Transduction/genetics , Superior Colliculi/cytology , Superior Colliculi/embryology , Superior Colliculi/metabolism , Transcription Factor Brn-3B , Transcription Factors/genetics , Transcription Factors/pharmacology , Visual Pathways/cytology
15.
Cell ; 97(5): 587-98, 1999 May 28.
Article in English | MEDLINE | ID: mdl-10367888

ABSTRACT

The mechanisms by which transient gradients of signaling molecules lead to emergence of specific cell types remain a central question in mammalian organogenesis. Here, we demonstrate that the appearance of four ventral pituitary cell types is mediated via the reciprocal interactions of two transcription factors, Pit1 and GATA2, which are epistatic to the remainder of the cell type-specific transcription programs and serve as the molecular memory of the transient signaling events. Unexpectedly, this program includes a DNA binding-independent function of Pit1, suppressing the ventral GATA2-dependent gonadotrope program by inhibiting GATA2 binding to gonadotrope- but not thyrotrope-specific genes, indicating that both DNA binding-dependent and -independent actions of abundant determining factors contribute to generate distinct cell phenotypes.


Subject(s)
DNA-Binding Proteins/metabolism , Pituitary Gland/cytology , Signal Transduction , Transcription Factors/metabolism , Transcription, Genetic , Amino Acid Sequence , Amino Acid Substitution , Animals , Base Sequence , COS Cells , DNA-Binding Proteins/chemistry , DNA-Binding Proteins/genetics , GATA2 Transcription Factor , Genes, Reporter , Homeodomain Proteins/metabolism , Mice , Mice, Transgenic , Molecular Sequence Data , Mutagenesis, Site-Directed , Pituitary Gland/metabolism , Point Mutation , Promoter Regions, Genetic , Rats , Recombinant Proteins/chemistry , Recombinant Proteins/metabolism , Thyrotropin/genetics , Transcription Factor Pit-1 , Transcription Factors/chemistry , Transcription Factors/genetics , Transfection , Zinc Fingers
16.
Genes Dev ; 13(4): 484-94, 1999 Feb 15.
Article in English | MEDLINE | ID: mdl-10049363

ABSTRACT

Pitx1 is a Bicoid-related homeodomain factor that exhibits preferential expression in the hindlimb, as well as expression in the developing anterior pituitary gland and first branchial arch. Here, we report that Pitx1 gene-deleted mice exhibit striking abnormalities in morphogenesis and growth of the hindlimb, resulting in a limb that exhibits structural changes in tibia and fibula as well as patterning alterations in patella and proximal tarsus, to more closely resemble the corresponding forelimb structures. Deletion of the Pitx1 locus results in decreased distal expression of the hindlimb-specific marker, the T-box factor, Tbx4. On the basis of similar expression patterns in chick, targeted misexpression of chick Pitx1 in the developing wing bud causes the resulting limb to assume altered digit number and morphogenesis, with Tbx4 induction. We hypothesize that Pitx1 serves to critically modulate morphogenesis, growth, and potential patterning of a specific hindlimb region, serving as a component of the morphological and growth distinctions in forelimb and hindlimb identity. Pitx1 gene-deleted mice also exhibit reciprocal abnormalities of two ventral and one dorsal anterior pituitary cell types, presumably on the basis of its synergistic functions with other transcription factors, and defects in the derivatives of the first branchial arch, including cleft palate, suggesting a proliferative defect in these organs analogous to that observed in the hindlimb.


Subject(s)
Avian Proteins , Hindlimb/growth & development , Homeodomain Proteins/genetics , Morphogenesis/genetics , Nuclear Proteins , Pituitary Gland/growth & development , T-Box Domain Proteins , Trans-Activators/genetics , Transcription Factors/genetics , Wings, Animal/growth & development , Animals , Branchial Region/embryology , Branchial Region/growth & development , Chick Embryo , Drosophila Proteins , Gene Deletion , Gene Expression Regulation, Developmental/genetics , Hindlimb/embryology , Homeodomain Proteins/metabolism , Immunohistochemistry , In Situ Hybridization , Mandible/embryology , Mandible/growth & development , Mice , Mice, Knockout , Paired Box Transcription Factors , Pituitary Gland/embryology , Trans-Activators/metabolism , Wings, Animal/embryology , Homeobox Protein PITX2
17.
Genes Dev ; 12(11): 1691-704, 1998 Jun 01.
Article in English | MEDLINE | ID: mdl-9620855

ABSTRACT

During development of the mammalian pituitary gland specific hormone-producing cell types, critical in maintaining homeostasis, emerge in a spatially and temporally specific fashion from an ectodermal primordium. We have investigated the molecular basis of generating diverse pituitary cell phenotypes from a common precursor, providing in vivo and in vitro evidence that their development involves three sequential phases of signaling events and the action of a gradient at an ectodermal boundary. In the first phase, the BMP4 signal from the ventral diencephalon, expressing BMP4, Wnt5a, and FGF8, represents a critical dorsal neuroepithelial signal for pituitary organ commitment in vivo. Subsequently, a BMP2 signal emanates from a ventral pituitary organizing center that forms at the boundary of a region of oral ectoderm in which Shh expression is selectively excluded. This BMP2 signal together with a dorsal FGF8 signal, appears to create opposing activity gradients that are suggested to generate overlapping patterns of specific transcription factors underlying cell lineage specification events, whereas Wnt4 is needed for the expansion of ventral pituitary cell phenotypes. In the third phase, temporally specific loss of the BMP2 signal is required to allow terminal differentiation. The consequence of these sequential organ and cellular determination events is that each of the hormone-producing pituitary cell types-gonadotropes, thyrotropes, somatotropes, lactotropes, corticotropes, and melanotropes-appear to be determined, in a ventral-to-dorsal gradient, respectively.


Subject(s)
Gene Expression Regulation, Developmental , Pituitary Gland/embryology , Pituitary Gland/physiology , Signal Transduction/physiology , Transforming Growth Factor beta , Amino Acid Sequence , Animals , Bone Morphogenetic Protein 2 , Bone Morphogenetic Protein 4 , Bone Morphogenetic Proteins/physiology , Embryonic and Fetal Development/physiology , Mice , Mice, Transgenic , Molecular Sequence Data
18.
Nat Genet ; 18(2): 147-9, 1998 Feb.
Article in English | MEDLINE | ID: mdl-9462743

ABSTRACT

Combined pituitary hormone deficiency (CPHD) in man denotes impaired production of growth hormone (GH) and one or more of the other five anterior pituitary hormones. Mutations of the pituitary transcription factor gene POU1F1 (the human homologue of mouse Pit1) are responsible for deficiencies of GH, prolactin and thyroid stimulating hormone (TSH) in Snell and Jackson dwarf mice and in man, while the production of adrenocorticotrophic hormone (ACTH), luteinizing hormone (LH) and follicle stimulating hormone (FSH) is preserved. The Ames dwarf (df) mouse displays a similar phenotype, and appears to be epistatic to Snell and Jackson dwarfism. We have recently positionally cloned the putative Ames dwarf gene Prop1, which encodes a paired-like homeodomain protein that is expressed specifically in embryonic pituitary and is necessary for Pit1 expression. In this report, we have identified four CPHD families with homozygosity or compound heterozygosity for inactivating mutations of PROP1. These mutations in the human PROP1 gene result in a gene product with reduced DNA-binding and transcriptional activation ability in comparison to the product of the murine df mutation. In contrast to individuals with POU1F1 mutations, those with PROP1 mutations cannot produce LH and FSH at a sufficient level and do not enter puberty spontaneously. Our results identify a major cause of CPHD in humans and suggest a direct or indirect role for PROP1 in the ontogenesis of pituitary gonadotropes, as well as somatotropes, lactotropes and caudomedial thyrotropes.


Subject(s)
Homeodomain Proteins/genetics , Hypopituitarism/genetics , Membrane Proteins , Pituitary Hormones/deficiency , Saccharomyces cerevisiae Proteins , Transcription Factors/genetics , Adolescent , Adult , Amino Acid Sequence , Animals , Carrier Proteins/genetics , Child , Conserved Sequence , Dwarfism/genetics , Female , Growth Hormone/deficiency , Heterozygote , Homeodomain Proteins/biosynthesis , Homeodomain Proteins/chemistry , Homozygote , Human Growth Hormone/deficiency , Humans , Male , Mice , Mice, Mutant Strains , Molecular Sequence Data , Pedigree , Phospholipid Transfer Proteins , Prolactin/deficiency , Sequence Alignment , Sequence Homology, Amino Acid , Thyrotropin/deficiency , Transcription Factors/biosynthesis , Transcription Factors/chemistry
19.
Nature ; 384(6607): 327-33, 1996 Nov 28.
Article in English | MEDLINE | ID: mdl-8934515

ABSTRACT

The gene apparently responsible for a heritable form of murine pituitary-dependent dwarfism (Ames dwarf, df) has been positionally cloned, identifying a novel, tissue-specific, paired-like homeodomain transcription factor, termed Prophet of Pit-1 (Prop-1). The df phenotype results from an apparent failure of initial determination of the Pit-1 lineage required for production of growth hormone, prolactin or thyroid-stimulating hormone, resulting in dysmorphogenesis and failure to activate Pit-1 gene expression. These results imply that a cascade of tissue-specific regulators is responsible for the determination and differentiation of specific cell lineages in pituitary organogenesis.


Subject(s)
DNA-Binding Proteins/genetics , Dwarfism, Pituitary/genetics , Homeodomain Proteins/genetics , Pituitary Gland, Anterior/embryology , Transcription Factors/genetics , Alleles , Amino Acid Sequence , Animals , Cell Lineage , Dwarfism, Pituitary/embryology , Female , Gene Expression , Homeodomain Proteins/physiology , Hypothalamus/physiology , Male , Mice , Mice, Inbred C57BL , Molecular Sequence Data , Pituitary Gland, Anterior/abnormalities , Pituitary Gland, Anterior/physiology , Point Mutation , Sequence Homology, Amino Acid , Signal Transduction , Transcription Factor Pit-1
20.
Proc Natl Acad Sci U S A ; 93(15): 7706-10, 1996 Jul 23.
Article in English | MEDLINE | ID: mdl-8755540

ABSTRACT

A novel OTX-related homeodomain transcription factor has been identified on the basis of its ability to interact with the transactivation domain of the pituitary-specific POU domain protein, Pit-1. This factor, referred to as P-OTX (pituitary OTX-related factor), is expressed in primordial Rathke's pouch, oral epithelium, first bronchial arch, duodenum, and hindlimb. In the developing anterior pituitary, it is expressed in all regions from which cells with distinct phenotypes will emerge in the mature gland. P-OTX is able to independently activate and to synergize with Pit-1 on pituitary-specific target gene promoters. Therefore, P-OTX may subserve functions in generating both precursor and specific cell phenotypes in the anterior pituitary gland and in several other organs.


Subject(s)
DNA-Binding Proteins/metabolism , Gene Expression Regulation, Developmental , Homeodomain Proteins/biosynthesis , Pituitary Gland, Anterior/embryology , Pituitary Gland, Anterior/metabolism , Transcription Factors/metabolism , Animals , Branchial Region/metabolism , Duodenum/metabolism , Embryonic and Fetal Development , Epithelium/metabolism , Gene Expression , Gene Library , Hindlimb , Homeodomain Proteins/metabolism , Mice , Molecular Sequence Data , Organ Specificity , Paired Box Transcription Factors , Phenotype , Transcription Factor Pit-1 , Transcriptional Activation , Transfection
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