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Primary adrenal insufficiency is life threatening and can present alone or in combination with other comorbidities. Here, we have described a primary adrenal insufficiency syndrome and steroid-resistant nephrotic syndrome caused by loss-of-function mutations in sphingosine-1-phosphate lyase (SGPL1). SGPL1 executes the final decisive step of the sphingolipid breakdown pathway, mediating the irreversible cleavage of the lipid-signaling molecule sphingosine-1-phosphate (S1P). Mutations in other upstream components of the pathway lead to harmful accumulation of lysosomal sphingolipid species, which are associated with a series of conditions known as the sphingolipidoses. In this work, we have identified 4 different homozygous mutations, c.665G>A (p.R222Q), c.1633_1635delTTC (p.F545del), c.261+1G>A (p.S65Rfs*6), and c.7dupA (p.S3Kfs*11), in 5 families with the condition. In total, 8 patients were investigated, some of whom also manifested other features, including ichthyosis, primary hypothyroidism, neurological symptoms, and cryptorchidism. Sgpl1-/- mice recapitulated the main characteristics of the human disease with abnormal adrenal and renal morphology. Sgpl1-/- mice displayed disrupted adrenocortical zonation and defective expression of steroidogenic enzymes as well as renal histology in keeping with a glomerular phenotype. In summary, we have identified SGPL1 mutations in humans that perhaps represent a distinct multisystemic disorder of sphingolipid metabolism.

Eric Vilain and colleagues identify missense mutations in the imprinted gene CDKN1C , encoding the p57KIP2 cyclin dependent kinase inhibitor, in individuals with IMAGe syndrome. IMAGe syndrome is a developmental disorder characterized by intrauterine growth restriction, metaphyseal dysplasia, adrenal hypoplasia congenita and genital anomalies. IMAGe syndrome (intrauterine growth restriction, metaphyseal dysplasia, adrenal hypoplasia congenita and genital anomalies) is an undergrowth developmental disorder with life-threatening consequences 1 . An identity-by-descent analysis in a family with IMAGe syndrome 2 identified a 17.2-Mb locus on chromosome 11p15 that segregated in the affected family members. Targeted exon array capture of the disease locus, followed by high-throughput genomic sequencing and validation by dideoxy sequencing, identified missense mutations in the imprinted gene CDKN1C (also known as P57KIP2 ) in two familial and four unrelated patients. A familial analysis showed an imprinted mode of inheritance in which only maternal transmission of the mutation resulted in IMAGe syndrome. CDKN1C inhibits cell-cycle progression 3 , and we found that targeted expression of IMAGe-associated CDKN1C mutations in Drosophila caused severe eye growth defects compared to wild-type CDKN1C , suggesting a gain-of-function mechanism. All IMAGe-associated mutations clustered in the PCNA-binding domain of CDKN1C and resulted in loss of PCNA binding, distinguishing them from the mutations of CDKN1C that cause Beckwith-Wiedemann syndrome, an overgrowth syndrome 4 .

LHX4 is a LIM homeodomain transcription factor involved in the early steps of pituitary ontogenesis. To date, 8 heterozygous LHX4 mutations have been reported as responsible of combined pituitary hormone deficiency (CPHD) in Humans. We identified 4 new LHX4 heterozygous allelic variants in patients with congenital hypopituitarism: W204X, delK242, N271S and Q346R. Our objective was to determine the role of LHX4 variants in patients' phenotypes. Heterologous HEK293T cells were transfected with plasmids encoding for wild-type or mutant LHX4. Protein expression was analysed by Western Blot, and DNA binding by electro-mobility shift assay experiments. Target promoters of LHX4 were cotransfected with wild type or mutant LHX4 to test the transactivating abilities of each variant. Our results show that the W204X mutation was associated with early GH and TSH deficiencies and later onset ACTH deficiency. It led to a truncated protein unable to bind to alpha-Gsu promoter binding consensus sequence. W204X was not able to activate target promoters in vitro. Cotransfection experiments did not favour a dominant negative effect. In contrast, all other mutants were able to bind the promoters and led to an activation similar as that observed with wild type LHX4, suggesting that they were likely polymorphisms. To conclude, our study underlines the need for functional in vitro studies to ascertain the role of rare allelic variants of LHX4 in disease phenotypes. It supports the causative role of the W204X mutation in CPHD and adds up childhood onset ACTH deficiency to the clinical spectrum of the various phenotypes related to LHX4 mutations.

Hypopituitarism, or the failure to secrete hormones produced by the anterior pituitary (adenohypophysis) and/or to release hormones from the posterior pituitary (neurohypophysis), can be congenital or acquired. When more than one pituitary hormone axis is impaired, the condition is known as combined pituitary hormone deficiency (CPHD). The deficiency may be primarily due to a hypothalamic or to a pituitary disorder, or concomitantly both, and has a negative impact on target organ function. This review focuses on the pathophysiology, diagnosis and management of anterior pituitary hormone deficiency in the pediatric age. Congenital hypopituitarism is generally due to genetic disorders and requires early medical attention. Exposure to toxicants or intrauterine infections should also be considered as potential etiologies. The molecular mechanisms underlying the fetal development of the hypothalamus and the pituitary are well characterized, and variants in the genes involved therein may explain the pathophysiology of congenital hypopituitarism: mutations in the genes expressed in the earliest stages are usually associated with syndromic forms whereas variants in genes involved in later stages of pituitary development result in non-syndromic forms with more specific hormone deficiencies. Tumors or lesions of the (peri)sellar region, cranial radiation therapy, traumatic brain injury and, more rarely, other inflammatory or infectious lesions represent the etiologies of acquired hypopituitarism. Hormone replacement is the general strategy, with critical periods of postnatal life requiring specific attention.

Background: Combined pituitary hormone deficiency (CPHD) presents a wide spectrum of pituitary gland disorders. The postnatal gonadotropic surge provides a useful period to explore the gonadotropic axis for assessing the presence of congenital hypogonadotropic hypogonadism (CHH). Aim: To explore the functioning of the hypothalamic-pituitary-gonadal axis in the postnatal gonadotropic surge for an early diagnosis of CHH in newborns or infants suspected of having CPHD. Subjects and Methods: A cohort of 27 boys under 6 months and 19 girls under 24 months of age with suspected hypopituitarism was studied. Serum concentrations of LH, FSH, testosterone, inhibin B, anti-Müllerian hormone (AMH) and estradiol were measured, and male external genitalia were characterized as normal or abnormal (micropenis, microorchidism and/or cryptorchidism). Results: CPHD was confirmed in 36 out of 46 patients. Low LH and testosterone levels were found in 66% of the hypopituitary males, in significant association with the presence of abnormal external genitalia. This abnormality had a positive predictive value of 93% for CHH. No significant association was observed between serum FSH, AMH and inhibin B and the patient's external genitalia. Conclusion: In newborn or infant boys with CPHD, LH and testosterone concentrations measured throughout the postnatal gonadotropic surge, together with a detailed evaluation of the external genital phenotype, facilitate the diagnosis of CHH at an early stage.

Abstract Context The pituitary gland is key for childhood growth, puberty, and metabolism. Pituitary dysfunction is associated with a spectrum of phenotypes, from mild to severe. Congenital hypopituitarism (CH) is the most commonly reported pediatric endocrine dysfunction, with an incidence of 1:4000, yet low rates of genetic diagnosis have been reported. Objective We aimed to unveil the genetic etiology of CH in a large cohort of patients from Argentina. Methods We performed whole exome sequencing of 137 unrelated cases of CH, the largest cohort examined with this method to date. Results Of the 137 cases, 19.1% and 16% carried pathogenic or likely pathogenic variants in known and new genes, respectively, while 28.2% carried variants of uncertain significance. This high yield was achieved through the integration of broad gene panels (genes described in animal models and/or other disorders), an unbiased candidate gene screen with a new bioinformatics pipeline (including genes with high loss-of-function intolerance), and analysis of copy number variants. Three novel findings emerged. First, the most prevalent affected gene encodes the cell adhesion factor ROBO1. Affected children had a spectrum of phenotypes, consistent with a role beyond pituitary stalk interruption syndrome. Second, we found that CHD7 mutations also produce a phenotypic spectrum, not always associated with full CHARGE syndrome. Third, we add new evidence of pathogenicity in the genes PIBF1 and TBC1D32, and report 13 novel candidate genes associated with CH (eg, PTPN6, ARID5B). Conclusion Overall, these results provide an unprecedented insight into the diverse genetic etiology of hypopituitarism.

Abstract Purpose Congenital hypopituitarism (CH) can present in isolation or with other birth defects. Mutations in multiple genes can cause CH, and the use of a genetic screening panel could establish the prevalence of mutations in known and candidate genes for this disorder. It could also increase the proportion of patients that receive a genetic diagnosis. Methods We conducted target panel genetic screening using single-molecule molecular inversion probes sequencing to assess the frequency of mutations in known hypopituitarism genes and new candidates in Argentina. We captured genomic deoxyribonucleic acid from 170 pediatric patients with CH, either alone or with other abnormalities. We performed promoter activation assays to test the functional effects of patient variants in LHX3 and LHX4. Results We found variants classified as pathogenic, likely pathogenic, or with uncertain significance in 15.3% of cases. These variants were identified in known CH causative genes (LHX3, LHX4, GLI2, OTX2, HESX1), in less frequently reported genes (FOXA2, BMP4, FGFR1, PROKR2, PNPLA6) and in new candidate genes (BMP2, HMGA2, HNF1A, NKX2-1). Conclusion In this work, we report the prevalence of mutations in known CH genes in Argentina and provide evidence for new candidate genes. We show that CH is a genetically heterogeneous disease with high phenotypic variation and incomplete penetrance, and our results support the need for further gene discovery for CH. Identifying population-specific pathogenic variants will improve the capacity of genetic data to predict eventual clinical outcomes.

Abstract Disclosure: S.M. Suco: None. A.C. Keselman: None. M.G. Ballerini: None. M.E. Rodriguez: None. M.G. Ropelato: None. S. Rosenbrock: None. D. Braslavsky: None. R.A. Rey: None. R.P. Grinspon: None. Introduction: Some children born SGA have an earlier pubertal onset and more rapid progression. Therefore, it is essential to identify the onset of puberty to proceed in a timely and appropriate manner. As it has also been suggested that there may be some gonadal dysfunction, the classic markers of pubertal onset, for example, testicular volume ≥ 4ml, may not be appropriate in these cases. Objective: To describe the clinical and biochemical characteristics of pubertal maturation in boys born SGA and determine parameters that best identify pubertal onset. Methods: We perform a retrospective, descriptive study of a cohort of boys born SGA with longitudinal follow-up, at a tertiary pediatric public hospital in Buenos Aires, Argentina. The subjects were selected from 1997 to 2023. Main outcome measures were serum levels of LH and AMH and testicular volume (TV). Additionally, height velocity, bone age, IGF1 and HOMA-IR were also collected to analyze its association with puberty. Pubertal onset was defined as serum LH ≥ 0.3 U/L and/or a decrease in serum AMH ≥ 30%. Results: The cohort included 25 boys born SGA, 24% were born prematurely and 60% were referred for short stature. In 18 boys (72%) AMH decline occurred with testicular volume < 4ml, at a median age of 9.8 yr (IQR 8.3 – 11 yr), and with median TV of 2ml. In 5 boys, LH was ≥ 0.3 U/L when AMH decline >30%. In 14 boys (56%) TV was <4ml when serum LH was ≥ 0.3 U/L. The median age for LH ≥0.3 was 11.3yr (IQR 10.4 – 12.2 yr), with a median TV of 3ml. In 3 boys the decrease in AMH occurred concomitantly with the increase in LH, while in 6 it occurred before.Alongside with the AMH decline, acceleration of bone age was observed in 35%, increase in growth velocity in 29%, increase in IGF1 concentrations in 24% and an increase in HOMA-IR in 26% of the boys. Concomitantly with an LH ≥0.3 U/L, acceleration of bone age was observed in 19%, increase in growth velocity in 25%, increase in IGF1 concentrations in 30% and an increase in HOMA-IR in 50% of the boys. Conclusion: The increase in testicular volume to 4ml, a classic parameter used as a marker of pubertal onset, may not be appropriate in a subgroup of children born SGA. Probably other parameters such as the increase in serum LH or the decrease in AMH should be considered. Presentation: 6/1/2024

Background Congenital Hypopituitarism is caused by genetic and environmental factors. Over 30 genes have been implicated in isolated and/or combined pituitary hormone deficiency. The etiology remains unknown for up to 80% of the patients, but most cases have been analyzed by limited candidate gene screening. Mutations in the PROP1 gene are the most common known cause, and the frequency of mutations in this gene varies greatly by ethnicity. We designed a custom array to assess the frequency of mutations in known hypopituitarism genes and new candidates, using single molecule molecular inversion probes sequencing (smMIPS). Methods We used this panel for the first systematic screening for causes of hypopituitarism in children. Molecular inversion probes were designed to capture 693 coding exons of 30 known genes and 37 candidate genes. We captured genomic DNA from 51 pediatric patients with CPHD (n = 43) or isolated GH deficiency (IGHD) (n = 8) and their parents and conducted next generation sequencing. Results We obtained deep coverage over targeted regions and demonstrated accurate variant detection by comparison to whole‐genome sequencing in a control individual. We found a dominant mutation GH1, p.R209H, in a three‐generation pedigree with IGHD. Conclusions smMIPS is an efficient and inexpensive method to detect mutations in patients with hypopituitarism, drastically limiting the need for screening individual genes by Sanger sequencing. We developed a sequencing panel to capture the coding exons of genes that cause hypopituitarism in 51 patients. We found a mutation in the GH1 gene that is responsible for familial isolated growth hormone deficiency type II.

Disclosure: D.G. Braslavsky: None. A.C. Keselman: None. M.G. Ballerini: None. S. Rosenbrock: None. N. Cappa: None. G. Negrete: None. G. Dech: None. M.G. Ropelato: None. S. Gamio: None. I. Bergada: None. Background Current safety of recombinant human growth hormone (rhGH) treatment arises mainly from postmarketing surveillance. Headache is a relatively frequent symptom in children under rhGH. Secondary intracranial hypertension (SIH), is an adverse effect (AE), usually occurring within the first 12 weeks of treatment associated to headaches. Permanent visual defects are the most feared complication. Scarce information exists regarding incidence and natural history of visual impairment under rhGH. Aim To evaluate visual impairment and/or optic nerve affection in children throughout early rhGH treatment. Materials and Methods Prospective interventional study conducted from February 2018 to January 2020. Children ≥4 yr who received rhGH treatment for growth hormone deficiency (GHD), 0.16-0.25 mg/kg/w; Turner syndrome (TS), small for gestational age (SGA), 0.33 mg/kg/w and Prader Willy Syndrome (PWS) 1 mg/m2/d. Patients were assessed at basal, 1, 3, and 6 months of treatment. Each visit included clinical variables (adherence, auxology, AE, presence of headache), serum IGF1, IGFBP3, glucose, insulin, aldosterone, plasma renin activity, electrolytes and ophthalmologic evaluation [fundoscopy, optical coherence tomography (OCT), retinal nerve fiber layer (RNFL), ganglionic eye complex, ocular ultrasound, intraocular pressure (IOP), autorefractometry, biomicroscopy]. Results Sixty patients were enrolled, 12 GHD, 11 ST, 31 SGA, 3 PWS, 3 TBI (23 females), with a median age of 8.08 yrs (ranged 4.24-15). Median height was -2.25 ± 1.05 SDS. Baseline ophthalmologic evaluation was normal. Abnormal ophthalmological findings were observed in 15/60 (25%). Twelve patients showed changes in OCT, spontaneous recovery occurred in 8, whereas persistence or worsening of RNFL thickening lead to an MRI assessment and lumbar puncture (LP) in 4 patients (1 GHD, 2 SGA, 1 ST); only one referred headache. LP revealed opening pressure of 19, 21, 22 and 30 mmHg, respectively, the latter assumed as SIH at the 1st month of treatment. In these four patients, during the findings of ocular abnormalities, they presented a mean IGF1 1.12 ± 1.04 SDS and IGFBP3 -0.02 ± 2.34 SDS. ΔBMI -0.45 ± 0.71 SDS. Prevalence of SIH was 1.6%. All four patients received acetazolamide; median time for RNFL improvement took 4 months (range 4-8). One patient developed post-dural puncture headache. Three had elevated IOP. Along the protocol 19/60 referred headache (26 events). Three of these patients with headaches had abnormal ophthalmological findings (2 mild changes in OCT; 1 elevated IOP). Conclusion We have demonstrated a marked prevalence of abnormal ophthalmological findings upon early rhGH treatment. These observations occurred in the absence of suggestive clinical symptoms, and conversely, headache did not predict SIH. The prevalence of SIH due to rhGH is higher than previously reported. Presentation: Thursday, June 15, 2023