M. Maghnie

Early-onset central diabetes insipidus is associated with de novo arginine vasopressin–neurophysin II or Wolfram syndrome 1 gene mutations

OBJECTIVE Idiopathic early-onset central diabetes insipidus (CDI) might be due to mutations of arginine vasopressin-neurophysin II (AVP-NPII (AVP)) or wolframin (WFS1) genes. DESIGN AND METHODS Sequencing of AVP and WFS1 genes was performed in nine children with CDI, aged between 9 and 68 months, and negative family history for polyuria and polydipsia. RESULTS Two patients carried a mutation in the AVP gene: a heterozygous G-to-T transition at nucleotide position 322 of exon 2 (c.322G>T) resulting in a stop codon at position 108 (p.Glu108X), and a novel deletion from nucleotide 52 to 54 (c.52_54delTCC) producing a deletion of a serine at position 18 (p.Ser18del) of the AVP pre-prohormone signal peptide. A third patient carried two heterozygous mutations in the WFS1 gene localized on different alleles. The first change was A-to-G transition at nucleotide 997 in exon 8 (c.997A>G), resulting in a valine residue at position 333 in place of isoleucine (p.Ile333Val). The second novel mutation was a 3 bp insertion in exon 8, c.2392_2393insACG causing the addition of an aspartate residue at position 797 and the maintenance of the correct open reading frame (p. Asp797_Val798insAsp). While similar WFS1 protein levels were detected in fibroblasts from healthy subjects and from the patient and his parents, a major sensitivity to staurosporine-induced apoptosis was observed in the patient fibroblasts as well as in patients with Wolfram syndrome. CONCLUSIONS Early-onset CDI is associated with de novo mutations of the AVP gene and with hereditary WFS1 gene changes. These findings have valuable implications for management and genetic counseling.

Midbrain-Hindbrain Involvement in Septo-Optic Dysplasia

BACKGROUND AND PURPOSE: Midbrain-hindbrain involvement in septo-optic dysplasia has not been well described, despite reported mutations of genes regulating brain stem patterning. We aimed to describe midbrain-hindbrain involvement in patients with septo-optic dysplasia and to identify possible clinical-neuroimaging correlations. MATERIALS AND METHODS: Using MR imaging, we categorized 38 patients (21 males) based on the presence (group A, 21 patients) or absence (group B, 17 patients) of visible brain stem anomalies. We measured height and anteroposterior diameter of midbrain, pons, and medulla, anteroposterior midbrain/pons diameter (M/P ratio), vermian height, and tegmento-vermian angle, and compared the results with 114 healthy age-matched controls. Furthermore, patients were subdivided based on the type of midline anomalies. The associations between clinical and neuroradiological features were investigated. Post hoc tests were corrected according to Bonferroni adjustment (pB). RESULTS: Patients with brain stem abnormalities had smaller anteroposterior pons diameter than controls (pB < .0001) and group B (pB = .012), higher M/P ratio than controls (pB < .0001) and group B (pB < .0001), and smaller anteroposterior medulla diameter (pB = .001), pontine height (pB = .00072), and vermian height (pB = .0009) than controls. Six of 21 patients in group A had thickened quadrigeminal plate, aqueductal stenosis, and hydrocephalus; 3 also had agenesis of the epithalamus. One patient had a short midbrain with long pons and large superior vermis. There was a statistically significant association between brain stem abnormalities and callosal dysgenesis (P = .011) and developmental delay (P = .035), respectively. CONCLUSION: Midbrain-hindbrain abnormalities are a significant, albeit underrecognized, component of the septo-optic dysplasia spectrum, and are significantly associated with developmental delay in affected patients.

Quantitative ultrasound detects bone changes following bone marrow transplantation in pediatric subjects with hematological diseases: A longitudinal study

Background: Bone marrow transplantation (BMT) is associated with bone morbidity. We investigated bone status with quantitative ultrasound (QUS) in pediatric patients with hematological diseases prior to and up to 3 yr following BMT. Methods: Phalangeal QUS measures for amplitude-dependent speed of sound (Ad-SoS) and bone transmission time (BTT) were obtained in 40 hematological patients (25 with malignant, 15 with non-malignant disease; 9.7±4.9 yr) before BMT and 6, 12, 24, and 36 months after BMT. Bone parameters were expressed as Z-scores based on age-sex-matched normal controls. Results: Mean Ad-SoS and BTT Z-scores were normal before BMT and reduced at 36 months (analysis of variance: p=0.0542 and p=0.0233). Ad-SoS and BTT Z-scores remained relatively stable in the first 6 months after BMT and then progressively decreased reaching a plateau at 12–36 months. In non-malignant patients, BTT Z-score decreased at 6–12 months (p=0.029) and subsequently increased, while in malignant patients BTT Z-score showed a decrease at 12–24 months. Pre-pubertal subjects displayed a drop of BTT Z-Score values at both 12 (p=0.023) and 36 months after BMT (p=0.049), while BTT Z-score remained relatively unchanged in pubertal subjects. Early impairment of BTT Z-score was found in patients who suffered acute graft versus host disease (GVHD) compared to patients without this clinical condition; BTT Z-score was lower at 36 months (p=0.045). Conclusions: Longitudinal assessment by QUS of pediatric BMT survivors evidenced that bone status is mildly affected up to 36 months after BMT, mainly in malignant patients, in pre-pubertal subjects at BMT and in patients who suffered acute GVHD.

Structural Abnormalities in Congenital Growth Hormone Deficiency

Until the advent of magnetic resonance imaging (MRI), only small advances were made in the field of pituitary imaging. MRI, however, led to an enormous increase in our detailed knowledge of pituitary morphology, thus improving the differential diagnosis of hypopituitarism. Indeed, MRI represents the examination method of choice for evaluating hypothalamic-pituitary-related endocrine diseases thanks to its ability to provide strongly contrasted high-resolution multiplanar and spatial images. Specifically, MRI allows for a detailed and precise anatomical study of the pituitary gland by differentiating between the anterior and posterior pituitary lobes. The MRI identification of pituitary hyperintensity in the posterior part of the sella, now considered a marker of neurohypophyseal functional integrity, has been the most striking finding for the diagnosis and understanding of some forms of “idiopathic” and permanent growth hormone deficiency (GHD). Published data show a number of correlations between pituitary abnormalities as observed on MRI and a patient’s endocrine profile. Indeed, several trends have emerged and have been confirmed: (1) normal MRI or anterior pituitary hypoplasia generally indicates isolated GHD which is transient and not confirmed after adult height achievement; (2) patients with MPHD seldom show a normal pituitary gland; (3) the classic triad of ectopic posterior pituitary gland, pituitary stalk hypoplasia/agenesis, and anterior pituitary gland hypoplasia is more frequently reported in MPHD patients and is generally associated with permanent GHD. Pituitary abnormalities have been reported in patients with GHD carrying mutations in several genes encoding transcription factors such as POU1F1, PROP1, HESX1, LHX3, LHX4, GLI2, PITX1, PITX2, SOX3, SOX2, and OTX2. Establishing endocrine and MRI phenotypes is extremely helpful in the selection and management of patients with hypopituitarism, both in terms of possible genetic counseling, as well as that of early diagnosis of evolving anterior pituitary hormone deficiencies.

PO2-15: Insulin tolerance test and GHRH plus arginine in the reassessment of pituitary function at adult height achievement

N . Di Iorgi1, M .C . Salerno2, M . Cappa3, S . Loche4, G . Radetti5, D . Capaldo6, A . Allegri7, F . Napoli8, A . Calcagno7, O .B . Iovovich9, S . Noli7, S . Parodi10, M . Maghnie1 . 1DINOGMI, Endocrine Unit, IRCCS G Gaslini, University of Genova, Genova, Italy, 2Traslational Medical Sciences, Pediatric Endocrinology Unit, University Federico II, Naples, Italy, 3Unit of Endocrinology and Diabetology, Bambino Gesu Children’s Hospital, IRCCS, Rome, Italy, 4Pediatric Endocrine Unit, Ospedale Microcitemico, Cagliari, Italy, 5Pediatrics, Regional Hospital, Bolzano, Italy, 6Traslational Medical Sciences, Pediatric Endocrinology Unit, Federico II, Naples, Italy, 7DINOGMI, Endocrine Unit, University of Genova, Genova, Italy, 8Endocrine Unit, IRCCS, G Gaslini, Genova, Italy, 9Divisione di Laboratorio, IRCCS, G Gaslini, Genova, Italy, 10Institute of Electronics, Computer and Telecommunication Engineering, National Research Council of Italy, Genova, Italy

Diagnosi radiologica dei difetti ipofisari in età pediatrica

RiassuntoLo studio dell’ipotalamo-ipofisi è fondamentale per la diagnosi delle patologie endocrine. La risonanza magnetica è la modalità d’elezione per valutare la morfologia ipotalamo-ipofisaria. Con l’avvento della biologia molecolare e delle tecniche di neuroimmagine è stato dimostrato che le differenze della morfologia ipofisaria alla RMN sono l’espressione di una gamma di patologie dell’adenoipofisi con prognosi diversa.