Pituitary stalk interruption syndrome: A rare case report and literature review.

RATIONALE: Pituitary stalk interruption syndrome (PSIS) is a congenital pituitary anatomical defect. It is characterized by the triad of thin or interrupted pituitary stalk, absent or ectopic posterior lobe, and hypoplastic or aplastic anterior lobe. Moreover, this condition is considered rare. PATIENT CONCERNS: A 23-year-old male patient presented with a history of short stature and hypogonadism. Laboratory assessment revealed low thyroxine, cortisol, and adrenocorticotropic hormone levels, which are consistent with adrenal insufficiency without hypoglycemia. The insulin-induced hypoglycemia tolerance test finding indicated growth hormone (GH) deficiency. Moreover, magnetic resonance imaging revealed an interrupted pituitary stalk, ectopic posterior pituitary, and hypoplastic anterior pituitary. This triad of symptoms was indicative of PSIS. DIAGNOSIS: INTERVENTIONS:: The patient was deficient in adrenaline, thyroxine, gonadal steroid, and GH. Thus, glucocorticoid replacement therapy was initiated, followed by euthyrox, androgen, and human chorionic gonadotropin treatment. Calcium tablets, calcitriol, and alendronate sodium were used for the management of osteoporosis. The patient was 164 cm tall, and his bone age was approximately 15 years old. However, owing to a poor economic condition, the family did not proceed with GH therapy. OUTCOMES: The patient did not present with adrenal or hypothyroidism crisis after receiving poly-hormonal replacement therapy. His secondary sexual characteristics began to develop. However, owing to a short treatment window period, the patient could not receive the required treatment. Hence, whether the patient would have a normal fertility function needs to be confirmed. LESSONS: PSIS is a rare disease with various clinical characteristics. During the neonatal period and infancy, the signs and symptoms of PSIS are often not evident. Therefore, diagnosis is delayed. The early detection of hormone deficiency and treatment initiation can affect both the quality of life and the prognosis of patients with PSIS. Thus, the diagnosis and treatment of this disease must be improved to help patients achieve a better quality of life and to prevent reproductive health problems.

A novel truncating variant of GLI2 associated with Culler-Jones syndrome impairs Hedgehog signalling.

BACKGROUND: GLI2 encodes for a transcription factor that controls the expression of several genes in the Hedgehog pathway. Mutations in GLI2 have been described as causative of a spectrum of clinical phenotypes, notably holoprosencephaly, hypopituitarism and postaxial polydactyl. METHODS: In order to identify causative genetic variant, we performed exome sequencing of a trio from an Italian family with multiple affected individuals presenting clinical phenotypes in the Culler-Jones syndrome spectrum. We performed a series of cell-based assays to test the functional properties of mutant GLI2. RESULTS: Here we report a novel deletion c.3493delC (p.P1167LfsX52) in the C-terminal activation domain of GLI2. Functional assays confirmed the pathogenicity of the identified variant and revealed a dominant-negative effect of mutant GLI2 on Hedgehog signalling. CONCLUSIONS: Our results highlight the variable clinical manifestation of GLI2 mutations and emphasize the value of functional characterisation of novel gene variants to assist genetic counselling and diagnosis.

Two novel heterozygous missense variations within the GLI2 gene in two unrelated Argentine patients.

Several heterozygous GLI2 gene mutations have been reported in patients with isolated GH deficiency (IGHD) or multiple pituitary hormone deficiency (MPHD) with or without other malformations. The primary aim of this study was to analyze the presence of GLI2 gene alterations in a cohort of patients with IGHD or MPHD and ectopic/absent posterior pituitary. The coding sequence and flanking intronic regions of GLI2 gene were amplified and directly sequenced from gDNA of 18 affected subjects and relatives. In silico tools were applied to identify the functional impact of newly found variants (Polyphen2, SIFT, Mutation Taster). We identified two novel heterozygous missense variations in two unrelated patients, p.Arg231Gln and p.Arg226Leu, located in the repressor domain of the protein. Both variations affect highly conserved amino acids of the Gli2 protein and were not found in the available databases. In silico tools suggest that these variations might be disease causing. Our study suggests that the GLI2 gene may be one of the candidate genes to analyze when an association of pituitary hormone deficiency and developmental defects in posterior pituitary gland. The highly variable phenotype found suggests the presence of additional unknown factors that could contribute to the phenotype observed in these patients.

Two novel heterozygous missense variations within the GLI2 gene in two unrelated argentine patients / Two novel heterozygous missense variations within the GLI2 gene in two unrelated Argentine patients

Several heterozygous GLI2 gene mutations have been reported in patients with isolated GH deficiency (IGHD) or multiple pituitary hormone deficiency (MPHD) with or without other malformations. The primary aim of this study was to analyze the presence of GLI2 gene alterations in a cohort of patients with IGHD or MPHD and ectopic/absent posterior pituitary. The coding sequence and flanking intronic regions of GLI2 gene were amplified and directly sequenced from gDNA of 18 affected subjects and relatives. In silico tools were applied to identify the functional impact of newly found variants (Polyphen2, SIFT, Mutation Taster). We identified two novel heterozygous missense variations in two unrelated patients, p.Arg231Gln and p.Arg226Leu, located in the repressor domain of the protein. Both variations affect highly conserved amino acids of the Gli2 protein and were not found in the available databases. In silico tools suggest that these variations might be disease causing. Our study suggests that the GLI2 gene may be one of the candidate genes to analyze when an association of pituitary hormone deficiency and developmental defects in posterior pituitary gland. The highly variable phenotype found suggests the presence of additional unknown factors that could contribute to the phenotype observed in these patients.

Mutaciones heterocigotas en el gen GLI2 fueron previamente comunicadas como causa de déficit aislado de hormona de crecimiento (IGHD) o déficit múltiple de hormonas hipofisarias (MPHD), con o sin otras malformaciones. El objetivo del estudio fue analizar la presencia de alteraciones en el gen GLI2 en un grupo de pacientes con IGHD o MPHD acompañado de neurohipófisis ectópica o ausente. La secuencia codificante y las regiones intrónicas flanqueantes del gen GLI2 fueron amplificadas y secuenciadas de manera directa a partir de ADN genómico extraído de sangre periférica proveniente de 18 sujetos afectados y sus familiares. Se utilizaron herramientas informáticas para predecir el impacto funcional de las nuevas variantes encontradas (Polyphen2, SIFT, Mutation Taster). Identificamos dos nuevas variantes heterocigotas con pérdida de sentido en dos pacientes no relacionados, p.Arg231Gln y p.Arg226Leu, localizadas en el dominio represor de la proteína. Estas variantes afectan aminoácidos altamente conservados en la secuencia proteica de GLI2 y no se encuentran informadas en las bases de datos disponibles. Las herramientas informáticas utilizadas sugieren que estas variantes pueden ser la causa del desarrollo de la enfermedad. Nuestro resultados indican que el gen GLI2 es uno de los genes candidatos a estudiar cuando existe una asociación entre déficit de hormonas hipofisarias y alteraciones en el desarrollo de la neurohipófisis. Se sugiere la existencia de otros factores adicionales que podrían contribuir a la variabilidad del fenotipo observado.

Pituitary Stalk Interruption Syndrome from Infancy to Adulthood: Clinical, Hormonal, and Radiological Assessment According to the Initial Presentation.

BACKGROUND: Patients with pituitary stalk interruption syndrome (PSIS) are initially referred for hypoglycemia during the neonatal period or growth retardation during childhood. PSIS is either isolated (nonsyndromic) or associated with extra-pituitary malformations (syndromic). OBJECTIVE: To compare baseline characteristics and long-term evolution in patients with PSIS according to the initial presentation. STUDY DESIGN: Sixty-seven patients with PSIS were included. Data from subgroups were compared: neonates (n = 10) versus growth retardation patients (n = 47), and syndromic (n = 32) versus nonsyndromic patients (n = 35). RESULTS: Neonates displayed a more severe hormonal and radiological phenotype than children referred for growth retardation, with a higher incidence of multiple hormonal deficiencies (100% versus 34%; P = 0.0005) and a nonvisible anterior pituitary lobe (33% versus 2%; P = 0.0017). Regular follow-up of growth might have allowed earlier diagnosis in the children with growth retardation, as decreased growth velocity and growth retardation were present respectively 3 and 2 years before referral. We documented a progressive worsening of endocrine impairment throughout childhood in these patients. Presence of extra-pituitary malformations (found in 48%) was not associated with more severe hormonal and radiological characteristics. Growth under GH treatment was similar in the patient groups and did not vary according to the pituitary MRI findings. CONCLUSIONS: PSIS diagnosed in the neonatal period has a particularly severe hormonal and radiological phenotype. The progressive worsening of endocrine impairment throughout childhood justifies periodic follow-up to check for additional hormonal deficiencies.

A case report of severe panhypopituitarism in a newborn delivered by a women with Turner syndrome.

Turner syndrome (TS) is a congenital disease caused by absence or structural abnormalities of sex chromosomes resulting in gonadal dysgenesis. Spontaneous pregnancies occur in 2-8% of patients, especially with mosaic kariotypes, however they are associated with increased risk of poor outcome both for mother and fetus. We report a 4-day-old male infant delivered by women with mosaic TS who was admitted to the pediatric intensive care unit and presented with severe panhypopituitarism as the early manifestation of pituitary stalk interruption syndrome (PSIS). To the best of our knowledge this is the first report of severe panhypopituitarism in a newborn borne by women with TS.

A rare case of type 1 diabetes mellitus with pituitary hypoplasia.

Growth failure and pubertal abnormalities are not uncommon in chronic uncontrolled metabolic diseases like diabetes mellitus. We present a young girl with uncontrolled type 1 diabetes mellitus, who presented with short stature and primary amenorrhea, and on evaluation was found to have anterior pituitary hypoplasia. In addition to uncontrolled diabetes mellitus, she presented with early onset growth failure and lack of spontaneous secondary sexual characteristics. She had central hypothyroidism and inappropriately normal gonadotropin levels. However her serum cortisol levels were normal. MRI of the sellar-suprasellar region revealed a small anterior pituitary gland with thinning of the pituitary stalk consistent with pituitary hypoplasia. While uncontrolled type 1 diabetes itself may cause growth retardation and pubertal abnormalities, this girl had coexisting pituitary maldevelopment - a rare co-existence of two major illnesses of unrelated etiologies. The partial pituitary hormonal deficiency, which spared the hypothalamo-pituitary-adrenal axis, may be due to a transcription factor defect.

Congenital adenohypophyseal hypoplasia associated with secondary hypothyroidism in a 2-week-old Portuguese water dog.

This report describes the histomorphological changes of central hypothyroidism (pituitary dependent) in several target organs of thyroid hormones of a Portuguese water dog, and contrasts those with the reported features of central hypothyroidism in German shepherd dogs, in which central hypothyroidism is a part of a combined pituitary hormonal deficiency.

SOX2 regulates the hypothalamic-pituitary axis at multiple levels.

Sex-determining region Y (SRY) box 2 (SOX2) haploinsufficiency causes a form of hypopituitarism in humans that is characterized by gonadotrophin deficiency known as hypogonadotrophic hypogonadism. Here, we conditionally deleted Sox2 in mice to investigate the pathogenesis of hypogonadotrophic hypogonadism. First, we found that absence of SOX2 in the developing Rathke pouch of conditional embryos led to severe anterior lobe hypoplasia with drastically reduced expression of the pituitary-specific transcription factor POU class 1 homeobox 1 (POU1F1) as well as severe disruption of somatotroph and thyrotroph differentiation. In contrast, corticotrophs, rostral-tip POU1F1-independent thyrotrophs, and, interestingly, lactotrophs and gonadotrophs were less affected. Second, we identified a requirement for SOX2 in normal proliferation of periluminal progenitors; in its absence, insufficient precursors were available to produce all cell lineages of the anterior pituitary. Differentiated cells derived from precursors exiting cell cycle at early stages, including corticotrophs, rostral-tip thyrotrophs, and gonadotrophs, were generated, while hormone-producing cells originating from late-born precursors, such as somatotrophs and POU1F1-dependent thyrotrophs, were severely reduced. Finally, we found that 2 previously characterized patients with SOX2 haploinsufficiency and associated hypogonadotrophic hypogonadism had a measurable response to gonadotropin-releasing hormone (GnRH) stimulation, suggesting that it is not the absence of gonadotroph differentiation, but rather the deficient hypothalamic stimulation of gonadotrophs, that underlies typical hypogonadotrophic hypogonadism.

The pituitary stalk transection syndrome: multifaceted presentation in adulthood.

The pituitary stalk transection syndrome was characterized after introducing the MRI scan in the evaluation of children with hypopituitarism. Its prevalence and natural history into adulthood have not been clearly established. We present 4 cases of stalk transection syndrome diagnosed by the adult endocrinologist that reflect its pleiotropic manifestations. In all cases, MRI showed pathognomonic findings with small anterior pituitary, diminutive or absent infundibulum and ectopic posterior pituitary at the median eminence. Clinical presentation occurred in childhood or the second decade of life. The hormonal deficits were variable in severity and onset, with adrenal insufficiency diagnosed in the second and forth decade in three patients, and absent in another. Growth hormone deficiency was diagnosed before age 10 in three cases and at age 20 in one case with normal spontaneous linear growth. Hypothyroidism had onset in the first or second decade of life and hypogonadism was diagnosed during work-up for lack of pubertal development in all cases. The pituitary stalk transection syndrome should be considered in patients who were previously thought to have idiopathic GH deficiency or multiple pituitary hormone deficiencies. Presence of MRI characteristics compatible with the pituitary stalk transection syndrome should prompt a full pituitary hormonal evaluation. Long-term follow-up by the adult endocrinologist is warranted as new hormone deficiencies might appear later in life.

A novel homozygous HESX1 mutation causes panhypopituitarism without midline defects and optic nerve anomalies.

OBJECTIVE: There are many genes reported to have been associated with combined pituitary hormone deficiencies, but mutations in HESX1 strongly correlate with septo-optic dysplasia. Our aim was to determine the cause of panhypopituitarism in our patient. PATIENTS AND METHODS: We studied an 8-month-old child having panhypopituitarism. The coding exons of PIT1, PROP1, LHX3, and HESX1 genes were amplified. Direct sequencing was done after denaturing HLPC. RESULTS: We identified a novel homozygous mutation (R160H) within the homeodomain of HESX1, which, to our knowledge, is the first to be described in humans. Neuroimaging studies revealed anterior pituitary aplasia, a normal posterior pituitary gland, and a thin pituitary stalk but no midline abnormalities. Optic nerve studies showed no pathology. This mutation is also carried in the parents of the affected child in a heterozygous pattern, suggesting an autosomal recessive inheritance. CONCLUSION: These data demonstrate that homozygous HESX1 mutation causing an R160H substitution can result in panhypopituitarism without midline defects.

A novel loss-of-function mutation in OTX2 in a patient with anophthalmia and isolated growth hormone deficiency.

Heterozygous mutations of the gene encoding transcription factor OTX2 were recently shown to be responsible for ocular as well as pituitary abnormalities. Here, we describe a patient with unilateral anophthalmia and short stature. Endocrine evaluation of the hypothalamic-pituitary axis revealed isolated growth hormone deficiency (IGHD) with small anterior pituitary gland, invisible stalk, ectopic posterior lobe, and right anophthalmia on brain magnetic resonance imaging. DNA was analyzed for mutations in the HESX1, SOX2, and OTX2 genes. Molecular analysis yielded a novel heterozygous OTX2 mutation (c.270A>T, p.R90S) within the homeodomain. Functional analysis revealed that the mutation inhibited both the DNA binding and transactivation activities of the protein. This novel loss-of-function mutation is associated with anophthalmia and IGHD in a patient of Sephardic Jewish descent. We recommend that patients with GH deficiency and ocular malformation in whom genetic analysis for classic transcription factor genes (PROP1, POU1F1, HESX1, and LHX4) failed to identify alterations should be checked for the presence of mutations in the OTX2 gene.

Cleft lip and palate results from Hedgehog signaling antagonism in the mouse: Phenotypic characterization and clinical implications.

BACKGROUND: The Hedgehog (Hh) pathway provides inductive signals critical for developmental patterning of the brain and face. In humans and in animal models interference with this pathway yields birth defects, among the most well-studied of which fall within the holoprosencephaly (HPE) spectrum. METHODS: Timed-pregnant C57Bl/6J mice were treated with the natural Hh signaling antagonist cyclopamine by subcutaneous infusion from gestational day (GD) 8.25 to 9.5, or with a potent cyclopamine analog, AZ75, administered by oral gavage at GD 8.5. Subsequent embryonic morphogenesis and fetal central nervous system (CNS) phenotype were respectively investigated by scanning electron microscopy and high resolution magnetic resonance imaging (MRI). RESULTS: In utero Hh signaling antagonist exposure induced a spectrum of craniofacial and brain malformations. Cyclopamine exposure caused lateral cleft lip and palate (CLP) defects attributable to embryonic deficiency of midline and lower medial nasal prominence tissue. The CLP phenotype was accompanied by olfactory bulb hypoplasia and anterior pituitary aplasia, but otherwise grossly normal brain morphology. AZ75 exposure caused alobar and semilobar HPE with associated median facial deficiencies. An intermediate phenotype of median CLP was produced infrequently by both drug administration regimens. CONCLUSIONS: The results of this study suggest that interference with Hh signaling should be considered in the CLP differential and highlight the occurrence of CNS defects that are expected to be present in a cohort of patients having CLP. This work also illustrates the utility of fetal MRI-based analyses and establishes a novel mouse model for teratogen-induced CLP.

Rational approach to the diagnosis of severe growth hormone deficiency in the newborn.

CONTEXT: Severe congenital GH deficiency (GHD) of the newborn is a rare disease, which can cause life-threatening hypoglycemias beginning in the first week of life. Reviews and consensus papers on the diagnosis of GHD repeatedly state the lack of a practical evidence-based approach to the diagnosis of GHD in the newborn. OBJECTIVE: Here we provide for the first time sound reference values and a diagnostic cutoff for the GH levels in newborns at the age between d 3 and 5. DESIGN, SETTING, AND PATIENTS: GH was measured in the eluate from 314 filter papers of the newborn screening test performed in our university hospital by using a highly sensitive human GH-ELISA. Reference data are compared with measurements from nine newborns with very high likelihood of having severe GHD, and cutoffs for the diagnostic work-up are defined. RESULTS: In the presence of clinical evidence, the diagnosis of neonatal GHD can be confirmed during the first week of life by a single randomly taken GH level less than 7 microg/liter with 100% sensitivity and 98% specificity on the basis of our assay method. GH content in newborn screening cards stored for almost 3 yr were not different from the content found in recently used screening cards indicating high immunological stability of GH over time. Therefore, the diagnostic approach can use stored screening cards. In addition, we observed a clear gender dichotomy in respect to GH, with healthy female newborns having significantly higher GH levels than males. Cigarette smoking during pregnancy was associated with higher, transient tachypnea of the newborn with lower GH levels. CONCLUSIONS: We provide the first rational approach to the diagnosis of severe GHD in the newborn and evidence for gender dichotomy of the neonatal GH axis.

[Late onset hypopituitarism due to hypoplasia of the adenohypophysis with invisible stalk and ectopic neurohypophysis in a 67-year-old patient]. / Inicio tardío de hipopituitarismo debido a hipoplasia adenohipofisaria y ausencia de tallo con neurohipófisis ectópica en un paciente de 67 años de edad.

Congenital hypopituitarism due to pituitary stalk and anterior pituitary hypoplasia accompanied by an ectopic posterior pituitary lobe is a rare disorder causing multiple hormone deficiencies. Clinical signs can be present at birth (hypoglycemia, prolonged jaundice and micropenis) and there can be severe growth restriction. Therefore, diagnosis is usually performed in childhood. We present the uncommon case of a 67-year-old man with hypopituitarism due to hypoplasia of the anterior pituitary and pituitary stalk together with an ectopic posterior pituitary who presented symptoms of hyponatremia due to adrenocorticotropic hormone deficiency.

Enlargement of the proximal pituitary stalk associated with spontaneous recovery from multiple pituitary hormone deficiencies.

We report the case of a child with multiple pituitary hormone deficiencies and a truncated pituitary stalk on MR imaging who had recovery of normal secretion of pituitary hormones in early adulthood. Follow-up MR imaging examination after recovery revealed marked enlargement of the proximal pituitary stalk. The case of our patient helps to explain the mechanism whereby some patients experience recovery of hormonal function.