: Development, Genetic and Epigenetic Abnormalities.

In the 30 years since the first report of parental imprinting in insulin-like growth factor 2 () knockout mouse models, we have learnt much about the structure of this protein, its role and regulation. Indeed, many animal and human studies involving innovative techniques have shed light on the complex regulation of expression. The physiological roles of IGF-II have also been documented, revealing pleiotropic tissue-specific and developmental-stage-dependent action.

Low Maternal DLK1 Levels at 26 Weeks Is Associated With Small for Gestational Age at Birth.

Detecting SGA (small for gestational age) during pregnancy improves the fetal and neonatal prognosis. To date, there is no valid antenatal biomarker of SGA used in clinical practice. Maternal circulating DLK1 (delta-like non-canonical notch ligand 1) levels have been shown to be significantly lower in pregnant women at 36 weeks of gestation (WG) who delivered a SGA newborn than in controls.

Screening of patients born small for gestational age with the Silver-Russell syndrome phenotype for DLK1 variants.

Silver-Russell syndrome (SRS) is a rare imprinting disorder associated with prenatal and postnatal growth retardation. Loss of methylation (LOM) on chromosome 11p15 is observed in 40 to 60% of patients and maternal uniparental disomy (mUPD) for chromosome 7 (upd(7)mat) in ~5 to 10%. Patients with LOM or mUPD 14q32 can present clinically as SRS.

Insights from the genetic characterization of central precocious puberty associated with multiple anomalies.

Study Question: Is there an (epi)genetic basis in patients with central precocious puberty (CPP) associated with multiple anomalies that unmasks underlying mechanisms or reveals novel genetic findings related to human pubertal control?

Summary Answer: In a group of 36 patients with CPP associated with multiple phenotypes, pathogenic or likely pathogenic (epi)genetic defects were identified in 12 (33%) patients, providing insights into the genetics of human pubertal control.

What Is Known Already: A few studies have described patients with CPP associated with multiple anomalies, but without making inferences on causalities of CPP. Genetic-molecular studies of syndromic cases may reveal disease genes or mechanisms, as the presentation of such patients likely indicates a genetic disorder.

Contribution of functionally assessed GHRHR mutations to idiopathic isolated growth hormone deficiency in patients without GH1 mutations.

Isolated growth hormone deficiency (IGHD) is a rare condition mainly caused by mutations in GH1. The aim of this study was to assess the contribution of GHRHR mutations to IGHD in an unusually large group of patients. All GHRHR coding exons and flanking intronic regions were sequenced in 312 unrelated patients with nonsyndromic IGHD.

Transcriptional profiling at the domain explains clinical overlap between imprinting disorders.

Imprinting disorders (IDs) often affect growth in humans, leading to diseases with overlapping features, regardless of the genomic region affected. IDs related to hypomethylation of the human 14q32.2 region and its domain are associated with Temple syndrome (TS14).

Contribution of LHX4 Mutations to Pituitary Deficits in a Cohort of 417 Unrelated Patients.

Context: LHX4 encodes a LIM-homeodomain transcription factor that is implicated in early pituitary development. In humans, only 13 heterozygous LHX4 mutations have been associated with congenital hypopituitarism.

Objective: The aims of this study were to evaluate the prevalence of LHX4 mutations in patients with hypopituitarism, to define the associated phenotypes, and to characterize the functional impact of the identified variants and the respective role of the 2 LIM domains of LHX4.

Functional characterization of a human POU1F1 mutation associated with isolated growth hormone deficiency: a novel etiology for IGHD.

POU1F1, a pituitary-specific POU-homeo domain transcription factor, plays an essential role in the specification of the somatotroph, lactotroph and thyrotroph lineages and in the activation of GH1, PRL and TSHβ transcription. Individuals with mutations in POU1F1 present with combined deficiency of GH, PRL and TSH. Here, we identified a heterozygous missense mutation with evidence of pathogenicity, at the POU1F1 locus, in a large family in which an isolated growth hormone deficiency segregates as an autosomal dominant trait.

Molecular screening of a large cohort of Moroccan patients with congenital hypopituitarism.

Background/objectives: Congenital hypopituitarism is a rare disease which, for most patients, has no identified molecular cause. We aimed to document the molecular basis of growth retardation in a Moroccan cohort.

Design/patients: 80 index cases [54 with isolated growth hormone deficiency (IGHD), 26 with combined pituitary hormone deficiency (CPHD)] were screened for molecular defects in GH1 (including LCR-GH1), GHRHR, GHSR, GHRH, PROP1, POU1F1, HESX1, LHX3, LHX4 and SOX3.

Screening of LHX2 in patients presenting growth retardation with posterior pituitary and ocular abnormalities.

Background: In humans, pituitary hormone deficiency may be part of a syndrome including extra-pituitary defects like ocular abnormalities. Very few genes have been linked to this particular phenotype. In the mouse, Lhx2, which encodes a member of the LIM (Lin-11, Isl-1, and Mec-3) class of homeodomain proteins, was shown to be expressed during early development in the posterior pituitary, eye, and liver, and its expression persists in adulthood in the central nervous system Lhx2(-/-) mice display absence of posterior pituitary and intermediate lobes, malformation of the anterior lobe, anophthalmia, and they die from anemia.

Symptomatic heterozygotes and prenatal diagnoses in a nonconsanguineous family with syndromic combined pituitary hormone deficiency resulting from two novel LHX3 mutations.

Context: Only 11 mutations have been reported in the transcription factor LHX3, known to be important for the development of the pituitary and motor neurons. All patients were homozygous, with various syndromic forms of combined pituitary hormone deficiency (CPHD), hampering to allocate, in these consanguineous patients, the respective contribution of LHX3 and additional genes to each symptom.

Objective: The aim of the study was to report the family history and the molecular basis of a nonconsanguineous patient with syndromic CPHD.

A novel POU1F1 mutation (p.Thr168IlefsX7) associated with an early and severe form of combined pituitary hormone deficiency: functional analysis and follow-up from infancy to adulthood.

Context: POU1F1 encodes a pituitary-specific homeodomain transcription factor that is crucial for development and differentiation of anterior pituitary cell types producing GH, TSH and PRL. Although the first mutations in humans were reported in 1992, to date, less than 25 different mutations of POU1F1 have been identified worldwide.

Objectives: To describe the long-term follow-up of a 22-year-old male of Israeli Arab Muslim origin, born to a consanguineous union, with congenital hypothyroidism, who presented with life-threatening hypoglycaemic episodes and severe growth retardation from infancy.

Unusual phenotypic features in a patient with a novel splice mutation in the GHRHR gene.

Isolated growth hormone deficiency (IGHD) may be of genetic origin. One of the few genes involved in that condition encodes the growth hormone releasing hormone receptor (GHRHR) that, through its ligand (GHRH), plays a pivotal role in the GH synthesis and secretion by the pituitary. Our objective is to describe the phenotype of two siblings born to a consanguineous union presenting with short stature (IGHD) and Magnetic Resonance Imaging (MRI) abnormalities, and to identify the molecular basis of this condition.

Oriented scanning is the leading mechanism underlying 5' splice site selection in mammals.

Splice site selection is a key element of pre-mRNA splicing. Although it is known to involve specific recognition of short consensus sequences by the splicing machinery, the mechanisms by which 5' splice sites are accurately identified remain controversial and incompletely resolved. The human F7 gene contains in its seventh intron (IVS7) a 37-bp VNTR minisatellite whose first element spans the exon7-IVS7 boundary.

Novel HESX1 mutations associated with a life-threatening neonatal phenotype, pituitary aplasia, but normally located posterior pituitary and no optic nerve abnormalities.

Context: Hesx1 is one of the earliest homeodomain transcription factors expressed during pituitary development. Very few HESX1 mutations have been identified in humans; although in those cases the disease phenotype shows considerable variability, all but one of the patients display an ectopic posterior pituitary and/or optic nerve abnormalities.

Objective: The objectives of the study were to describe the complex phenotype associated with the panhypopituitarism of two unrelated Italian patients who, at birth, presented with hypoglycemic seizures and respiratory distress complicated by shock, in a familial context of neonatal death in one family and spontaneous miscarriage in both families and to identify the molecular basis of this unusual syndrome.

Alu-element insertion in the homeodomain of HESX1 and aplasia of the anterior pituitary.

The pathophysiology of combined pituitary hormone deficiency is just beginning to be elucidated. None of the genes known to be necessary for pituitary development has so far been involved in pituitary gland aplasia in humans. Among these, Hesx1/HESX1, which encodes a homeobox transcription factor, has been shown to be essential for normal forebrain development in mice, and HESX1 mutations in humans have been associated with various pituitary hormone deficiencies usually combined with optic nerve anomalies.

Factor VII gene intronic mutation in a lethal factor VII deficiency: effects on splice-site selection.

In a patient with lethal factor VII (FVII) deficiency, 2 homozygous nucleotide substitutions were identified in the F7 gene: a IVS7+2T>G transversion involving the IVS7 donor splice site, followed by a mutation at nucleotide 10588 that would result in a missense variation (Arg224Gln). The mutated splice site, located within the first repeat of a minisatellite, is followed by a variable number of pseudo-sites, normally silent. To investigate the consequences of this mutation on F7 splicing, we designed normal and mutant minigenes, spanning exons 5 to 8.