Hormonal, pituitary magnetic resonance, LHX4 and HESX1 evaluation in patients with hypopituitarism and ectopic posterior pituitary lobe

Pituitary stalk interruption syndrome: A rare cause of amenorrhea in a patient with normal stature and secondary sexual characteristics

Pituitary stalk interruption syndrome (PSIS) is a rare disorder characterized by the imaging triad of thinned or absent pituitary stalk, ectopic posterior pituitary lobe, and hypoplastic or absent anterior lobe. Patients typically present with 1 or more anterior pituitary lobe hormone deficits, most commonly growth hormone or gonadotropin, but patients may achieve normal stature and secondary sexual characteristics. Here, we present a case of a young female patient presenting with amenorrhea, normal stature, and sexual development, and an imaging triad of PSIS. To our knowledge, this is the first case of PSIS to present with hyperprolactinemia and an otherwise normal pituitary hormone profile.

Partial ectopic posterior pituitary: A rare imaging entity with literature review

Abnormal development of the posterior pituitary gland can lead to an ectopic location of the neurohypophysis, commonly seen at the median eminence of the hypothalamus or along the infundibular stalk. A partial ectopic posterior pituitary (PEPP) is a very rare variant of the ectopic posterior pituitary, defined as the presence of a double bright spot of neurohypophysis seen in both orthotopic and ectopic locations. We report a two-year-old male toddler with bilateral optic nerve hypoplasia and severe visual impairment who presented to the endocrine outpatient clinic for hypopituitarism evaluation. Magnetic resonance imaging (MRI) of the brain revealed a hypoplastic pituitary gland and infundibulum with a double bright spot of neurohypophysis in the expected normal location and along the median eminence. Severe hypoplasia of both optic nerves and the optic chiasm was also seen. Septum pellucidum was present with no evidence of other brain malformations. The findings are in the septo-optic dysplasia spectrum associated with hypothalamic-pituitary dysfunction and a very rare entity called PEPP. To our knowledge, only a handful of reported cases of this rare entity exist in the literature.

Clinico-radiological correlation of pituitary stalk interruption syndrome in children with growth hormone deficiency

PURPOSE

To analyze the clinical, hormonal, and radiological characteristics of Pituitary stalk interruption syndrome (PSIS) in children with growth hormone deficiency (GHD).

METHODS

This is a prospective cross-sectional study, conducted over a period of three years in a short stature clinic of tertiary care referral hospital. 57 severe short stature children with proven GHD were included in the study.

RESULTS

Among 57 children with GHD, 14 (24%) were diagnosed as PSIS. The mean age at diagnosis was 11.8 ± 2.6years. The male to female ratio was 2.5:1. Nine (64%) children had multiple pituitary hormone deficiency (MPHD) and 5 (36%) had isolated growth hormone deficiency (IGHD). In spite of absent or ectopic posterior pituitary (EPP)in Magnetic Resonance Imaging (MRI) of PSIS cohorts, only one had Arginine vasopressin (AVP) deficiency. EPP was seen near median eminence in 6 (44%), elsewhere in 4 (28%), and absent in 4 (28%)children. The height gain following growth hormone therapy was better in PSIS cohorts as compared to non-PSIS.

CONCLUSION

Male gender, breech presentation, external congenital anomalies like cryptorchidism, midline defects and nystagmus were more common in children with PSIS. MPHD were more frequently seen in PSIS whereas IGHD in non-PSIS cohort. AVP deficiency is very rare in PSIS despite of absent or ectopic posterior pituitary in MRI. High index of clinical suspicion in all severe short stature may lead to early diagnosis and prompt initiation of growth hormone treatment for better outcome.

Pituitary stalk interruption syndrome: phenotype, predictors, and pathophysiology of perinatal events

PURPOSE

There is limited data regarding Pituitary Stalk Interruption Syndrome (PSIS) from India. Moreover, the pathophysiological link between perinatal events and PSIS is unclear. We aim to elucidate the predictors of PSIS among patients with growth hormone deficiency (GHD) and perinatal events in PSIS by comparing cohorts of PSIS and genetically proven GHD without PSIS.

METHODS

Among 179 GHD patients, 56 PSIS and 70 genetically positive GHD (52-GHRHR, 15-POU1F1, and 3-PROP1) patients were included. Perinatal events, clinical anomalies, pituitary hormone deficiency, and imaging findings were recorded. We compared PSIS-isolated GHD (PSIS-IGHD) subgroup with GHRHR-IGHD and PSIS-combined pituitary hormone deficiency (PSIS-CPHD) subgroup with POU1F1/PROP1-CPHD.

RESULTS

PSIS patients (45 males, median age: 12.5 years) most commonly presented with short stature. At last follow-up (median age: 17.35 years), gonadal (during pubertal-age), thyroid and cortisol axes were affected in 81.6%, 62.5%, and 62.5%. 10/13 (77%) of PSIS children with initial IGHD diagnosis manifested hypogonadism during pubertal age. Male predominance, sporadic presentation, and clinical anomalies were significantly higher in both PSIS subgroups than in the respective genetic subgroups. Breech presentation was higher in PSIS-CPHD than POU1F1/PROP1-CPHD (44.4% vs 5.5%, p = 0.004). Neonatal hypoglycemia (22% vs. 0%, p = 0.05) and jaundice (42 vs. 5%, p = 0.004) were higher in PSIS-CPHD than PSIS-IGHD.

CONCLUSION

Later age at presentation and frequent hypogonadism were observed in our PSIS cohort. Male sex, sporadic presentation, clinical anomalies, and breech presentation predicted PSIS at presentation. Breech presentation in PSIS is likely due to stalk interruption rather than hormonal deficiency.

Pituitary stalk interruption syndrome is characterized by genetic heterogeneity

Pituitary stalk interruption syndrome is a rare disorder characterized by an absent or ectopic posterior pituitary, interrupted pituitary stalk and anterior pituitary hypoplasia, as well as in some cases, a range of heterogeneous somatic anomalies. A genetic cause is identified in only around 5% of all cases. Here, we define the genetic variants associated with PSIS followed by the same pediatric endocrinologist. Exome sequencing was performed in 52 (33 boys and 19 girls), including 2 familial cases single center pediatric cases, among them associated 36 (69.2%) had associated symptoms or syndromes. We identified rare and novel variants in genes (37 families with 39 individuals) known to be involved in one or more of the following-midline development and/or pituitary development or function (BMP4, CDON, GLI2, GLI3, HESX1, KIAA0556, LHX9, NKX2-1, PROP1, PTCH1, SHH, TBX19, TGIF1), syndromic and non-syndromic forms of hypogonadotropic hypogonadism (CCDC141, CHD7, FANCA, FANCC, FANCD2, FANCE, FANCG, IL17RD, KISS1R, NSMF, PMM2, SEMA3E, WDR11), syndromic forms of short stature (FGFR3, NBAS, PRMT7, RAF1, SLX4, SMARCA2, SOX11), cerebellum atrophy with optic anomalies (DNMT1, NBAS), axonal migration (ROBO1, SLIT2), and agenesis of the corpus callosum (ARID1B, CC2D2A, CEP120, CSPP1, DHCR7, INPP5E, VPS13B, ZNF423). Pituitary stalk interruption syndrome is characterized by a complex genetic heterogeneity, that reflects a complex phenotypic heterogeneity. Seizures, intellectual disability, micropenis or cryptorchidism, seen at presentation are usually considered as secondary to the pituitary deficiencies. However, this study shows that they are due to specific gene mutations. PSIS should therefore be considered as part of the phenotypic spectrum of other known genetic syndromes rather than as specific clinical entity.

A Novel Missense Mutation in Human Receptor Roundabout-1 (ROBO1) Gene Associated with Pituitary Stalk Interruption Syndrome

Pituitary stalk interruption syndrome (PSIS) is characterized by the association of an absent or thin pituitary stalk, an absent or hypoplastic anterior pituitary lobe and an ectopic posterior pituitary (EPP) lobe. The causes of this anatomical defect include both genetic and environmental factors. Molecular genetic defects have been indentified in a small number of patients with PSIS. A 4-year-old boy presented with hypoglycemia and hyponatremia associated with growth hormone, thyroid stimulating hormone, and adrenocorticotropic hormone deficiencies. The patient had right sided strabismus. magnetic resonance imaging images showed pituitary hypoplasia, EPP and absent pituitary stalk. A novel Receptor Roundabout-1 (ROBO1) missense mutation (c.1690C>T, p.Pro564Ser) that may contribute to the disorder was found in this patient and his mother, who also exhibited pituitary abnormalities.

NBPF9 Gene May Be Involved in Congenital Hypopituitarism: A Whole-Genome Study of a Boy with Pituitary Stalk Interruption Syndrome and His Family

Pituitary stalk interruption syndrome (PSIS) is a rare congenital defect manifesting as various degrees of anterior pituitary hormone deficiency. Scattered familial cases have been found, revealing some genetic variants. However, most of the previous research studies involved an affected sibling, and the gene spectra of the patients' entire family have rarely been reported. We conducted a study of a family consisting of a PSIS patient with his unaffected sibling and healthy parents of Han Chinese background using whole-genome sequencing. Bioinformatic analysis was carried out, and mutations related to PSIS, single-nucleotide variants (SNVs), insertion-deletion (InDELs), and structural variations (SVs) in all the four samples were filtered. After Sanger sequencing, we confirmed the variants obtained and selected three candidate genes for functional verification. The gene variations in this boy with PSIS and his lineal relatives are reported herein; de novo sequencing revealed that the NBPF9 gene may be involved in the pathogenesis of PSIS.

A new imaging entity consistent with partial ectopic posterior pituitary gland: report of six cases

BACKGROUND

Abnormal posterior pituitary development including ectopic location has been associated with endocrine manifestations of anterior pituitary dysfunction.

OBJECTIVE

We describe an unreported clinical and radiologic entity we call partial ectopic posterior pituitary for which associated endocrine consequences are not known.

MATERIALS AND METHODS

We selected pediatric head MRI examinations from 2005 to 2017 based on the finding of a double midline sellar and suprasellar bright spot on T1-weighted sequence. Medical history, physical examination, pituitary hormonal profile and bone age evaluation were extracted from the medical record of the selected patients. An experienced pediatric neuroradiologist reviewed head MRIs, which were performed on 3-tesla (T) magnet and included at least sagittal T1-weighted imaging centered on the sella turcica obtained with and without fat suppression.

RESULTS

In six cases, two midline bright spots were identified on T1-weighted sequences obtained both with and without fat suppression. While one spot was located at the expected site of the neurohypophysis in the posterior sella, the second one was in the region of the median eminence, suggesting partial ectopic posterior pituitary gland. Growth hormone deficiency, either isolated (n=1) or combined with thyroid stimulating hormone deficiency (n=1) was found. None of the children had clinical signs of posterior pituitary dysfunction.

CONCLUSION

We describe an unreported imaging entity suggesting partial ectopic posterior pituitary gland in six children. Anterior pituitary hormone deficiencies might be detected in those children and long-term follow-up could provide additional information on the development of other pituitary hormone deficiencies.

SCREENING OF PROP-1, LHX2 AND POU1F1 MUTATIONS IN PATIENTS WITH ECTOPIC POSTERIOR PITUITARY GLAND

OBJECTIVE

Ectopic posterior pituitary gland (EPP) is usually characterized by an abnormal pituitary stalk and hypoplasia of the anterior hypophysis. The genetic mechanisms involved in the development of EPP remain uncertain. The aim of this study is to determine whether mutations in the three genes, PROP-1, LHX2, and POU1F1, are associated with the risk for and the characteristics of EPP.

METHODS

In the Endocrinology Outpatient Clinic of "Dr. Behcet Uz" Children's Hospital, 27 patients with EPP were submitted to sequencing analyses of the PROP-1, LHX2, and POU1F1 genes.

RESULTS

Growth hormone, thyrotropin, corticotropin, gonadotropin, and vasopressin deficiency were observed in 22 (81.5%), 23 (85.2%), 17 (63%), 14 (51.9%), and two (7.4%) patients. Thirteen patients (48.1%) presented with hyperprolactinemia. Fourteen patients (51%) had a history of birth dystocia, and 12 cases (42.1%) had a history of breech presentation. Central nervous system abnormalities included five cases with corpus callosum agenesis, one case with schizencephaly, and one case with Chiari type 1 malformation. We identified a homozygous p.S109* mutation in exon 2 in one male patient with EPP and two different PROP1 gene polymorphisms (A142T or c.109+3 G>A polymorphism) in thirteen patients.

CONCLUSIONS

Our results suggest that PROP1 gene abnormalities might explain the genetic mechanisms involved in the development of EPP.

Multi-genic pattern found in rare type of hypopituitarism: a whole-exome sequencing study of Han Chinese with pituitary stalk interruption syndrome

Pituitary stalk interruption syndrome (PSIS) is a rare type of hypopituitarism manifesting various degrees of pituitary hormone deficiency. Although mutations have been identified in some familial cases, the underpinning mechanisms of sporadic patients with PSIS who are in a vast majority remain elusive, necessitating a comprehensive study using systemic approaches. We postulate that other genetic mechanisms may be responsible for the sporadic PSIS. To test this hypothesis, we conducted a study in 24 patients with PSIS of Han Chinese with no family history using whole‐exome sequencing (WES) and bioinformatic analysis. We identified a group of heterozygous mutations in 92% (22 of 24) of the patients, and these genes are mostly associated with Notch, Shh, Wnt signalling pathways. Importantly, 83% (20 of 24) of the patients had more than one mutation in those pathways suggesting synergy of compound mutations underpin the pathogenesis of sporadic PSIS.

Genetics of Combined Pituitary Hormone Deficiency: Roadmap into the Genome Era

The genetic basis for combined pituitary hormone deficiency (CPHD) is complex, involving 30 genes in a variety of syndromic and nonsyndromic presentations. Molecular diagnosis of this disorder is valuable for predicting disease progression, avoiding unnecessary surgery, and family planning. We expect that the application of high throughput sequencing will uncover additional contributing genes and eventually become a valuable tool for molecular diagnosis. For example, in the last 3 years, six new genes have been implicated in CPHD using whole-exome sequencing. In this review, we present a historical perspective on gene discovery for CPHD and predict approaches that may facilitate future gene identification projects conducted by clinicians and basic scientists. Guidelines for systematic reporting of genetic variants and assigning causality are emerging. We apply these guidelines retrospectively to reports of the genetic basis of CPHD and summarize modes of inheritance and penetrance for each of the known genes. In recent years, there have been great improvements in databases of genetic information for diverse populations. Some issues remain that make molecular diagnosis challenging in some cases. These include the inherent genetic complexity of this disorder, technical challenges like uneven coverage, differing results from variant calling and interpretation pipelines, the number of tolerated genetic alterations, and imperfect methods for predicting pathogenicity. We discuss approaches for future research in the genetics of CPHD.

Growth Hormone Therapy Benefits Pituitary Stalk Interruption Syndrome Patients with Short Stature: A Retrospective Study of 75 Han Chinese

Objective. We aim to investigate the long-term benefits of growth hormone (GH) therapy in short stature adolescents and adults with pituitary stalk interruption syndrome (PSIS), which would be beneficial for future clinical applications. Design and Methods. In this study, initial height, final height, total height gain, and GH treatment history were retrospectively investigated in 75 Chinese PSIS patients. We compared height gain between the GH treated cohort and untreated cohort and explored the impact of different GH therapy duration on height gain. Results. For GH treated patients, their final height (SDS) increased from -1.99 ± 1.91 (-6.93~2.80) at bone age (BA) of 11.2 (5.0~17.0) years to -1.47 ± 1.64 (-7.82~1.05) at BA of 16.6 (8.0~18.0) years (P = 0.016). And GH treated patients had more height gain than the untreated patients (P < 0.05). There was a significant difference between the different GH therapy duration groups (P = 0.001): GH 0 versus GH 3, P = 0.000; GH 1 versus GH 3, P = 0.028; GH 2 versus GH 3, P = 0.044. Conclusion. Adult Chinese PSIS patients with short stature benefited the most from at least 12 months of GH therapy. Although patient diagnosis age was lagged behind in the developing countries, GH treatment was still effective for them and resulted in a higher final height and more height gain.

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.

Pituitary stalk interruption syndrome: Case report of three cases with review of literature

Pickardt syndrome (Pickardt-Fahlbusch syndrome) is a rare congenital syndrome characterized by tertiary hypothyroidism caused by the interruption of the portal veins between hypothalamus and adenohypophysis. Typical features of this syndrome are tertiary hypothyroidism with low thyroid stimulating hormone, hyperprolactinemia and other pituitary hormone deficiencies. Pituitary stalk interruption syndrome is characterized by a triad of thin or interrupted pituitary stalk, aplasia or hypoplasia of the anterior pituitary and absent or ectopic posterior pituitary (EPP) seen on magnetic resonance imaging (MRI). It is a congenital anomaly of pituitary whose exact prevalence is unknown. In some cases, it is restricted to EPP or pituitary stalk interruption. We are presenting the case history along with MRI finding of three children's who presented with short stature and delayed puberty.

Pituitary stalk interruption syndrome in 53 postpubertal patients: factors influencing the heterogeneity of its presentation

BACKGROUND

Pituitary stalk interruption syndrome (PSIS) may induce an isolated growth hormone (GH) deficiency or multiple hypothalamic-pituitary (HP) deficiencies. Patients with multiple HP deficiencies, primarily those with adrenocorticotropin (ACTH) deficiency, are at increased risk of morbidity and mortality. Our objective was to identify the factors influencing each symptom and the MRI features of the syndrome to enhance its diagnosis and genetic analysis.

METHODS

This study was a retrospective, single-center, case-cohort study of 53 patients with PSIS who had reached pubertal age.

RESULTS

Patients were classified as having an isolated GH deficiency (n = 24, Group 1) or HP deficiencies (n = 29, Group 2); of these, 19 had complete HP deficiency, and 10 had GH deficiency associated with TSH (n = 4), TSH and ACTH (n = 3), TSH and gonadotropin (n = 1) deficiencies or amenorrhea (n = 2). The following features were less frequent in Group 1 than in Group 2: breech presentation (4% vs 35%, P = 0.008), hypoglycemia (0% vs 59%, P<0.00001), micropenis (13% vs 69%, P<0.003), hypothalamic origin (0% vs 52%, P<0.000001), ophthalmic malformation (8% vs 38%, P<0.02) and psychomotor delay (0% vs 31%, P<0.004). The frequencies of all other malformations were similar in both groups (37% vs 59%). A visible pituitary stalk was characteristic of patients belonging to Group 1 (P<0.0002). The GH peak was greater in Group 1 than in Group 2 (P<0.0003), as was the anterior pituitary height (P = 0.01).

CONCLUSION

The factors that best discriminate patients with multiple HP deficiencies from those with an isolated GH deficiency are breech presentation, hypoglycemia, and micropenis. No patient with an isolated GH deficiency had psychomotor delay, but associated malformations and/or syndromes, with the exception of ophthalmic disorders, occurred with similar frequencies in both groups. We have also shown that each of the above characteristics is associated with a given HP deficiency and/or malformation/syndrome in the majority of cases.

Candidate genes for panhypopituitarism identified by gene expression profiling

Mutations in the transcription factors PROP1 and PIT1 (POU1F1) lead to pituitary hormone deficiency and hypopituitarism in mice and humans. The dysmorphology of developing Prop1 mutant pituitaries readily distinguishes them from those of Pit1 mutants and normal mice. This and other features suggest that Prop1 controls the expression of genes besides Pit1 that are important for pituitary cell migration, survival, and differentiation. To identify genes involved in these processes we used microarray analysis of gene expression to compare pituitary RNA from newborn Prop1 and Pit1 mutants and wild-type littermates. Significant differences in gene expression were noted between each mutant and their normal littermates, as well as between Prop1 and Pit1 mutants. Otx2, a gene critical for normal eye and pituitary development in humans and mice, exhibited elevated expression specifically in Prop1 mutant pituitaries. We report the spatial and temporal regulation of Otx2 in normal mice and Prop1 mutants, and the results suggest Otx2 could influence pituitary development by affecting signaling from the ventral diencephalon and regulation of gene expression in Rathke's pouch. The discovery that Otx2 expression is affected by Prop1 deficiency provides support for our hypothesis that identifying molecular differences in mutants will contribute to understanding the molecular mechanisms that control pituitary organogenesis and lead to human pituitary disease.

Effects of genetic variability of the caprine homeobox transcription factor HESX1 gene on performance traits

HESX1 plays a key role in the development of the forebrain and pituitary gland and produces potential effects on performance traits. The objective of this study was to detect and assess the associations of the possible polymorphisms of six loci within HESX1 gene with performance traits in Chinese 1,119 goats. Only one novel SNP (NM_001494116:g.307049A > G) locating on IVS1 + 348A > G was identified and detected by HaeIII forced-RFLP-PCR. The frequencies of allele "G" varied from 0.025 to 0.245 in analyzed populations with the Hardy-Weinberg equilibrium (P > 0.05). Genotypic and allelic frequencies were found to be significantly different in four breeds (chi(2) = 147.674, df = 6, P < 0.001; chi(2) = 157.250, df = 3, P < 0.001, respectively), implying that the distribution of genotypic and allelic frequencies of goat HESX1 gene was significantly associated with different goat utilities (cashmere, meat and dairy). Association analysis results revealed no significant effects of caprine HESX1 gene on body sizes in XNSN population (P > 0.05) and cashmere traits in IMWC population (P > 0.05). Significant statistical of HESX1 gene with body weight was found (*P < 0.05). The genotype AA showed significantly higher body weight than those of AG in 2-year-old age (*P < 0.05), while the AA genotype was senior to AG genotype in 4-year-old body weight trait (*P < 0.05). These suggestions indicated that the HESX1 gene has significant effect on goat body weight depending on ages, which is accordance with the function repressor of the HESX1.

Heterozygous mutation of HESX1 causing hypopituitarism and multiple anatomical malformations without features of septo-optic dysplasia

Isolated GH deficiency or combined pituitary hormone deficiencies have been associated with mutations in transcription factors encoding genes that control organogenesis or cell differentiation. Among these factors, Hesx1 is essential for the development of the optic nerve and regulates some of the earliest stages in pituitary development and is intimately involved in orchestrating the expression of other factors involved in pituitary organogenesis. Mutations in HESX1 are reported in patients with hypopituitarism either with typical septo-optic dysplasia (SOD) or with neuromorphological abnormalities not included in classical SOD. The present report describes clinical features, biochemical parameters, and characterization of a missense mutation (Gln6His) in exon1 of HESX1 in a pre-pubertal child who progressively developed multiple hypopituitarism, firstly GH and, afterwards, TSH and ACTH deficiencies, in a pluri-malformative syndrome characterized by short stature and anatomical malformations not associated with a classical SOD phenotype. This finding further supports the necessity to stay alert in evaluating a gene that plays a minor role in the pathogenesis of sporadic hypopituitarism, such as HESX1 gene even when the phenotype does not fit in with a classical SOD syndrome.