Aldosterone signaling defect in young infants: single-center report and review.

BACKGROUND: Aldosterone (Ald) is a crucial factor in maintaining electrolyte and water homeostasis. Defect in either its synthesis or function causes salt wasting (SW) manifestation. This disease group is rare, while most reported cases are sporadic. This study aimed to obtain an overview of the etiology and clinical picture of patients with the above condition and report our rare cases. METHODS: A combination of retrospective review and case studies was conducted at the Pediatric Endocrine unit of The First Affiliated Hospital Sun Yat Sen University from September 1989 to June 2020. RESULTS: A total of 187 patients with SW were enrolled, of which 90.4% (n = 169) were diagnosed with congenital adrenal hyperplasia (CAH). SW type 21-hydroxylase deficiency accounted for 98.8% (n = 167) of CAH diagnosis, while 1.2% (n = 2) was of lipoid CAH. Non-CAH comprised 9.6% (n = 18) of the total patients whose etiologies included SF-1 gene mutation (n = 1), X-linked adrenal hypoplasia congenita (n = 9), aldosterone synthase deficiency (ASD, n = 4), and pseudo-hypoaldosteronism type 1 (PHA1, n = 1). Etiologies were not identified in three patients. All of patients with ASD and PHA1 exhibited SW syndrome in their early neonatal period. DNA sequencing showed mutations of CYP11B2 for P1-P4 and NR3C2 for P5. P1 and P2 were sibling brothers affected by compound heterozygous mutations of c.1121G > A (p.R374Q) and c.1486delC p.(L496fs); likewise, P4 was identified with compound heterozygous mutations of c.1200 + 1G > A and c.240-1 G > T; meanwhile P3 demonstrated c.1303G > A p.(G435S) homozygous mutation in CYP11B2 gene. Lastly, P5 showed c.1768 C > T p.(R590*) heterozygous mutation in the NR3C2 gene. CONCLUSION: Etiology of infant with aldosterone defect was mostly congenital. Renal and adrenal imaging are recommended to exclude renal causes. If clinical picture is suggestive, normal plasma Ald in early infancy cannot rule out aldosterone insufficiency.

[Efficacy of letrozole in treatment of male adolescents with idiopathic short stature].

ObjectiveTo evaluate the efficacy and safety of aromatase inhibitor letrozole in treatment of male adolescents with idiopathic short stature (ISS). MethodSeventy five boys with height less than 2 standard deviation (SD) below the mean who had entered puberty were enrolled in our study from 2004 to 2017, in the Pediatric Department of the First Affiliated Hospital, Sun Yat-Sen University. Among 75 patients, 28 in letrozole group received letrozole and spironolactone, 30 in gonadotrophin releasing hormone analogue (GnRHa) group received GnRHa injection and 17 had no intervention. Height velocity (HV), increment of bone age/chronological age (ΔBA/ΔCA), the final adult height (FAH) were compared among groups and the safety of letrozole treatment was evaluated. ResultsHV maintained faster during letrozole treatment when compared with other groups. HV during GnRHa treatment showed slightly decline in the first 6 months, but decreased remarkably after 6 months, and was significantly lower than that in letrozole group ( P < 0.05). The maturation of BA slowed down in both letrozole and GnRHa groups. But the ΔBA/ΔCA in letrozole group during the first and the second year of treatment were significantly higher (0.67±0.09, 0.50±0.15, respectively) when compared with GnRHa group (0.59±0.16, 0.44±0.13, respectively) ( t=2.78 and 2.20, all P < 0.05). FAH in letrozole group and GnRHa group were (170±4) cm and (170±6)cm, there was no significant differences between the two groups ( P>0.05), and both were higher than that in no intervention group (162±4 cm, P < 0.01). After 6 months of letrozole treatment, testicular volumes and serum testerone levels increased; 39.2% (11/28) boys had clinical manifestations of hyperandrogenemia, and 82.1% (23/28) boys had decreased serum high-density lipoprotein (HDL) levels. Serum levels of HDL and testerone returned normal and the hyperandrogenemia disappeared after the cessation of letrozole treatment. No significant changes in serum triglyceride, serum low-density lipoprotein (LDL), fating serum levels of insulin and glucose, HOMA-IR were observed. No abnormal liver function, myalgia, scoliosis or aggravations of scoliosis was found. ConclusionsLong term letrozole therapy during puberty in boys with ISS can delay bone maturation without significant decrease of linear growth, and thus can improve the final adult height. No severe adverse reactions were found.

The pubertal development mode of Chinese girls with turner syndrome undergoing hormone replacement therapy.

BACKGROUND: Further knowledge about the pubertal development mode of girls with Turner syndrome (TS) who have undergone hormone replacement therapy (HRT) is beneficial to the proposal of an optimal HRT regimen. This study examined the pubertal development mode of girls with TS who underwent HRT and evaluated the characteristics of optimal sex induction therapy in girls with TS. METHOD: We conducted a retrospective, longitudinal study over the past two decades at The First Affiliated Hospital, Sun Yat-sen University. PATIENTS: Seventy-one patients with TS and two groups of normal Chinese girls. RESULTS: The total investigation time was 3.00 (2.00, 4.66) years. The interval of each stage was significantly longer (P < 0.001) in the girls with TS than that in the normal Chinese girls, except for B2-3 (P = 0.011). The uterine volumes of the girls with TS in stages B2 and 3 were greater than those of the control group (P = 0.046), whereas the uterine volume of the control group was inversely greater than that of the TS group among those who reached stages B4 and 5 (P = 0.034). During HRT, the uterine volume grew significantly from all previous stages except for breast stage 5 (B3 vs.2: Z = - 2.031; P = 0.042; B4 vs. 3: Z = - 2.273; P = 0.023; B5 vs. 4: Z = - 1.368; P = 0.171). The paired data of 27 girls with TS showed that the uterine volume (17.93 ± 9.31 ml vs. 13.75 ± 6.67 ml) and width (2.54 ± 0.66 cm vs. 2.22 ± 0.36 cm) increased significantly during artificial cycles compared with before artificial cycles (t = - 2.79 and - 2.51, P = 0.01 and 0.018). CONCLUSION: HRT led to normal breast development in girls with TS; half of the girls with TS in our study reached Tanner stage B5, although the uterus ultimately developed suboptimally. The girls' breasts and uteruses grew quickly at the beginning of HRT (stages B2-4). An optimal HRT regimen for girls with TS may specifically focus on Tanner stages B2-4 and artificial cycles.

Low serum adiponectin levels are associated with reduced insulin sensitivity and lipid disturbances in short children born small for gestational age.

BACKGROUND: Being born as small for gestational age (SGA) has an increased risk of developing metabolic/cardiovascular disturbances in later life. The role of adiponectin in the metabolic disturbance in SGA children remained undefined. OBJECTIVE: The aim of this study was to investigate the association between serum levels of adiponectin and insulin sensitivity as well as lipid profile in short children born SGA at prepubertal ages. PATIENTS AND METHODS: Serum levels of adiponectin, fasting glucose, insulin, IGF-I, IGFBP-1, total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglycerides (TG), apolipoprotein A-I (ApoA-I) and Apo B were measured in 30 prepubertal short children born SGA. Insulin resistance (IR) and ß-cell function were assessed using the method of homeostatic model (HOMA). Data were compared to those of 30 short appropriate for gestational age (AGA) children matched for age, gender, height and body mass index, and correlation analysis was performed. RESULTS: Short SGA children had significantly higher levels of fasting insulin, HOMA-IR and HOMA-ß but lower levels of adiponectin than short AGA controls. No significant differences in the level of IGFBP-1 and IGF-I were found between the two groups. Serum levels of TC, TG, Apo B and Apo B/ApoA-I ratio were significantly higher in SGA, with 33% of hypercholesteraemia and 23% of hyperglyceridaemia. Stepwise multiple regression analysis revealed that serum adiponectin level was negatively correlated with HOMA-IR and TG and was positively correlated with birthweight SDS in SGA children. CONCLUSIONS: These findings suggest that low serum adiponectin levels are associated with reduced insulin sensitivity and unfavourable lipid profiles in short children born SGA at prepubertal ages.

Therapeutic effects of growth hormone combined with low-dose stanozolol on growth velocity and final height of girls with Turner syndrome.

OBJECTIVE: Turner syndrome (TS), which is characterized by short stature and gonadal dysfunction, is managed by pharmacotherapy. This study aimed to investigate the therapeutic effects of recombinant human growth hormone (rhGH) combined with low-dose stanozolol on the growth and final adult height (FAH) of girls with Turner syndrome (TS). DESIGN: Prospective study. PATIENTS: A total of 44 girls with TS were treated with rhGH (47·6-52·4 µg/kg/day) and low-dose stanozolol (20-35 µg/kg/day), starting at a mean age of 12·65 ± 1·99 year. The control group consisted of 22 girls with TS, who did not receive treatment. MEASUREMENTS: Subjects' growth velocity (GV) was investigated. Height standard deviation score (HtSDS) was calculated relative to healthy Chinese girls (HtSDSN or ) as well as untreated Chinese girls with TS (HtSDSTS ). Post-treatment follow-up was performed until the subjects achieved FAH or near FAH. RESULTS: FAH was significantly higher in subjects receiving treatment compared to the untreated controls (151·42 vs 137·75 cm, P < 0·001). GV was significantly higher in the first to fourth years of treatment compared to baseline values (P < 0·001); it was significantly lower in the second to fourth years of treatment compared to the first year (P < 0·001). CONCLUSIONS: In girls with TS, 9-12 years of age, rhGH combined with low-dose stanozolol may effectively increase growth. At least a 2-year course of this treatment may effectively improve FAH with proper delay of oestrogen-induced development.

[Mutation analysis for a Chinese family featuring X-linked alpha thalassemia/mental retardation syndrome].

OBJECTIVE: To identify potential mutation in a Chinese family featuring X-linked alpha thalassemia/mental retardation syndrome (ATR-X). METHODS: Based on clinical symptoms and inheritance pattern, linkage analysis of X chromosome short tandem repeats (X-STR) loci was carried out to locate the candidate gene. Subsequently, sequences of exons and exon-intron boundaries of the candidate gene were amplified with polymerase chain reaction (PCR). Potential mutations were detected by direct DNA sequencing. All patients were also analyzed for the trait of thalassemia. RESULTS: Linkage analysis indicated the candidate gene to be ATRX. Subsequently, a homozygous missense mutation c.736C>T (p.R246C) was found in exon 9 of ATRX in all of the 3 patients. And a heterozygous mutation c.736C>T (p.R246C) was also identified in the patient's mother and grandmother. Similar mutations were not detected in other members of the family. Alpha thalassemia was detected in the proband and another patient, whose genotypes were determined as -α(3.7)/αα and --(sea)/αα, respectively. CONCLUSION: Missense mutation of c.736C>T in ATRX gene is a mutation hotspot, and p.R246C may disturb the function of ATRX-DNMT3-DNMT3L domain (ADD), which may be responsible for the disease in this family.

[Rapid prenatal genetic diagnosis of a fetus with a high risk for Morquio A syndrome].

OBJECTIVE: To provide rapid and accurate prenatal genetic diagnosis for a fetus with high risk of Morquio A syndrome. METHODS: Based on ascertained etiology of the proband and genotypes of the parents, particular mutations of the GALNS gene were screened at 10th gestational week with amplification refractory mutation system (ARMS), denaturing high performance liquid chromatography (DHPLC), and direct DNA sequencing. RESULTS: DHPLC screening has identified abnormal double peaks in the PCR products of exons 1 and 10, whilst only a single peak was detected in normal controls. Amplification of ARMS specific primers derived a specific product for the fetus's gene, whilst no similar product was detected in normal controls. Sequencing of PCR products confirmed that exons 1 and 10 of the GALNS gene from the fetus contained a heterozygous paternal c.106-111 del (p.L36-L37 del) deletion and a heterozygous maternal c.1097 T>C (p.L366P) missense mutation, which resulted in a compound heterozygote status. CONCLUSION: The fetus was diagnosed with Morquio A syndrome and a genotype similar to the proband. Termination of the pregnancy was recommended. Combined ARMS, DHPLC and DNA sequencing are effective for rapid and accurate prenatal diagnosis for fetus with a high risk for Morquio A syndrome. Such methods are particularly suitable for early diagnosis when pathogenesis is clear. Furthermore, combined ARMS and DHPLC are suitable for rapid processing of large numbers of samples for the identification of new mutations.

Pleomorphism of the HPG axis with NR0B1 gene mutation - a case report of longitudinal follow-up of a proband with central precocious puberty.

OBJECTIVES: X-linked adrenal hypoplasia congenita (AHC) is characterized by adrenal insufficiency and hypogonadotropic hypogonadism. Herein, we report a rare case of X-linked AHC with central precocious puberty (CPP). CASE PRESENTATION: An 11-month-old male patient was found to have premature pubarche, enlargement of the penis, and frequent erection. LH and FSH levels after the GnRHa test were in the pubertal range. Direct sequencing revealed a heterozygous variant of the NR0B1 gene. The proband was treated with hydrocortisone and 9-alpha fludrocortisone because of the significantly elevated ACTH and renin activity. The secondary sexual characteristics relieved gradually. The serum testosterone and LH subsequently returned to the prepubertal range. The basal serum FSH values have been between 1.0 and 2.0 IU/L since the age of 2.25 years, with extremely low AMH levels beginning at 3 years. CONCLUSIONS: The clinical course of CPP with NR0B1 variant may be temporary. HPG axis status of X-linked AHC may probably be pleomorphic during the longitudinal follow-up.

Gonadal Y-chromosome mosaicism with 45, X Turner syndrome complicated with bilateral HCG-secreting gonadoblastoma.

We report a rare case of bilateral HCG-secreting gonadoblastomas (Gb) in a 5.25-year-old girl of 45, X Turner syndrome (TS) with gonadal Y chromosome mosaicism. The clinical data were summarized, and the literatures were reviewed. The patient had enlarged breasts for 2 years and 3 months, with elevated ß-HCG of blood found for 8 months. The level of ß-HCG of cerebrospinal fluid, cranial MRI, chest and abdominal CT, and pelvic MRI were normal. After surgical gonad exploration, biopsy and excision, gonad venous blood hormone examination and SRY gene detection of gonad tissue, the diagnosis was confirmed as HCG-secreting Gb (bilateral) and TS (45, X) with gonad Y chromosome mosaicism. The patient received 4 courses of chemotherapy, and regular outpatient follow-up. At 9 months after gonadectomy, there was no clinical, laboratory, or radiological evidence of recurrence. We reported a nonclassical case of 45, X Turner syndrome (TS) with gonadal Y chromosome mosaicism, who presented with breast development as the first manifestation and then virilization due to bilateral HCG-secreting gonadoblastomas. Detection of serum ß-HCG and AFP is requisite for the diagnosis of precocious puberty, karyotyping is important for virilizing phenotypic female, and virilization in Turner syndrome implies the existence of Y chromosome(substance) (peripheral blood or tissue mosaicism) and the occurrence of gonadal tumors.

[Human chorionic gonadotropin-secreting gonadoblastomas in a girl of 45, X Turner syndrome: a case report and literature review].

Objective: To summarize the experience in diagnosis and treatment of 45, X Turner syndrome (TS) with gonadal Y chromosome mosaicism and bilateral gonadoblastoma (Gb) secreting human chorionic gonadotrophin(HCG). Methods: A female patient aged 5 years and 3 months was admitted to the hospital with a complaint of "enlarged breasts for 27 months, and elevated blood ß-HCG for 8 months". The clinical data were summarized, and related literature up to March 2022 with the key words"Turner syndrome" "Gonadoblastoma" "Y chromosome" "human chorionic gonadotropin" "precocious" in PubMed, CNKI and Wanfang databases were reviewed. Results: The girl went to the local hospital for 2-month breast development at age of 3 years, and was found with a heart murmur diagnosed with "pulmonary venous malformation and atrial septal defect (secondary foramen type)". Surgical correction was performed. She experienced the progressive breast development, rapid linear growth and markedly advanced skeletal age, which cannot be explained by partial activation in the hypothalamic-pituitary-gonadal axis determined at the age of 3 years and 7 months in local hospital. Then whole-exome sequencing revealed chromosome number abnormality 45, X, which was confirmed by Karyotyping. At the age of 4 years and 6 months, serum ß-HCG was found to be elevated (24.9 U/L) with no lesion found at the local hospital. On physical examination, she was found with breast development, pubic hair development and clitoromegaly with elevated serum testosterone (1.96 µg/L) and ß-HCG (32.3 U/L). Sex determining region Y(SRY) gene was negative in peripheral blood sample. Thoracic and abdominal CT, head and pelvic magnetic resonance imaging were normal. Exploratory laparotomy confirmed the presence of a left adnexal tumor and a right fibrous streak gonad. During surgery, simultaneous samples of bilateral gonadal and peripheral venous blood were obtained and serum ß-HCG, estradiol and testosteron concentrations was higher to lower from left gonadal venous blood, right gonadal venous blood, to peripheral venous blood. Bilateral gonadectomy was performed. Histopathology revealed bilateral gonadoblastomas. SRY was positive in bilateral gonadal tissues. After surgery, serum E2, testerone and ß-HCG returned to normal. So far 4 cases of HCG-secreting gonadoblastoma had been reported worldwide. The phenotypes of the 4 cases were all female, with virilization or amenorrhea, and the preoperative peripheral blood ß-HCG concentrations were 74.4, 5.0, 40 456.0, and 42.4 U/L, respectively. Conclusions: There is a high risk of Gb in TS with Y chromosome components. Gb is infrequently presented with breast development, and Gb associated with HCG secretion is rare. Karyotyping should be performed in a phenotypic female with masculinization, and virilization in TS indicates the presence of Y chromosome material with concurrent androgen secreting tumors.

Association between height and weight catch-up growth with insulin resistance in pre-pubertal Chinese children born small for gestational age at two different ages.

This study was performed to test whether children born small for gestational age (SGA) with catch-up growth (CUG) could be associated with the early development of insulin resistance and the ß-cell dysfunction and to explore the impacts of height CUG and weight CUG on the insulin resistance in a Chinese population. A total of 30 children born SGA with CUG, 37 non-CUG (NCUG), and 42 born appropriate for gestational age (AGA) with normal height were recruited. Their fasting serum insulin, fasting glucose, insulin-like growth factor-1 (IGF-1) concentrations, and the homeostasis assessment model for insulin resistance (HOMA-IR) and ß-cell function (HOMA%) were evaluated. The values of HOMA-IR in CUG SGA were significantly higher than that in NCUG SGA (P = 0.002) and AGA children (P = 0.036), respectively. Correlation analysis revealed that the concentrations of fasting serum insulin were positively correlated with IGF-1 (r = 0.443, P = 0.001) and Δheight standard deviation score (SDS; r = 0.500, P = 0.002) in ≤ 6-year-old SGA children, but only with Δweight SDS (r = 0.496, P = 0.030) in >6-year-old children. In conclusion, SGA children with CUG in height and a higher body mass index are prone to the development of insulin resistance. Higher levels of insulin were closely correlated with the postnatal height CUG in young SGA children and with the weight CUG in old children.

Epidermal growth factor receptor signalling mediates growth hormone-induced growth of chondrocytes from sex hormone-inhibited adolescent rats.

1. Growth hormone (GH) has been demonstrated to overcome the inappropriate deceleration of growth rate in children with central precocious puberty treated with gonadotropin-releasing hormone analogue (GnRHa). However, the underlying mechanisms remain largely unclear. In the present study, we investigated the potential involvement of the epidermal growth factor receptor (EGFR) pathway in the growth promotion by GH using in vitro cultured growth plate chondrocytes isolated from adolescent rats treated with GnRHa. 2. Chondrocytes were stimulated with GH in the presence or absence of the Janus tyrosine kinase (JAK) 2 inhibitor AG490 (1, 10 and 100 nmol/L), the EGFR kinase inhibitor AG1478 (0.1, 1 and 10 nmol/L), U0126 (an inhibitor of extracellular signal-regulated kinase (Erk) activation; 10 µmol/L) or a neutralizing antibody against epidermal growth factor (EGF Ab; 0.1, 1 and 10 µg/mL). The proliferation of chondrocytes was assessed by the 3-(4,5-dimethyl-2 thiazoyl)-2,5-diphenyl-2H-tetrazolium bromide assay and immunostaining for proliferating cell nuclear antigen (PCNA). Phosphorylation of Erk1/2 and EGFR was detected by western-blotting. Intracellular mRNA and extracellular protein levels of EGF were detected using reverse transcription-polymerase chain reaction and ELISA, respectively. 3. Growth hormone promoted the proliferation of chondrocytes, which was correlated with increased phosphorylation of Erk1/2 and EGFR and enhanced expression of EGF. Pretreatment with AG490, AG1478, U0126 or EGF Ab completely or partially inhibited the proliferation of chondrocytes and activation of Erk1/2 and EGFR. Pretreatment with AG490, AG1478, or U0126 partially inhibited the expression of EGF. 4. The findings indicate that GH promotes chondrocyte proliferation by activating EGFR signalling.

Two cases of Fanconi-Bickel syndrome: first report from China with novel mutations of SLC2A2 gene.

Fanconi-Bickel syndrome (FBS) is a rare inherited disease caused by mutations in the glucose transporter 2 gene, SLC2A2. We reported the first two Chinese cases of FBS. Both cases presented typical clinical features of hepatomegaly, hypophosphatemic rickets, severely stunted growth, fasting hypoglycemia along with postprandial hyperglycemia, and proximal renal tubular dysfunction with disproportionately severe glucosuria. Genetic analysis of SLC2A2 gene revealed novel compound heterozygous mutations in both patients. The characteristics of being born as small for gestational age and apparent liver dysfunction in our cases have been seldom discussed in the literature. It seems FBS patients in general have lower birth weight than normal, but further data collection is still needed. Symptomatic treatments were effective, but the serum transaminase of patient 2 remained moderately increased, and he patient needed further follow-up. The present study will supplement the up-to-date clinical characteristic spectrum for FBS.

Clinical characteristics of adrenocortical tumors in children.

BACKGROUND: Adrenocortical tumors (ACTs) are rare in children. Because of the rarity and various manifestations of ACTs, patients of ACTs are not easily diagnosed. Some patients were misdiagnosed before surgery. OBJECTIVE: Identify the clinical, laboratorial, imaging and histopathological characteristics of adrenocortical tumors in children. Compare adrenalcortical adenoma with carcinoma. METHODS: A retrospective review of 34 identified patients who were younger than 15 years old with histologic confirmation of adrenocortical carcinoma (ACC) or adenomas from 1991 to 2010. RESULTS: In these 34 patients, 19 were adrenocortical adenoma (ACA) and 15 were ACC. The median age at diagnosis was 3.33 years (range, 0-16 years), and 70.6% of the patients were younger than five years. Girls slightly predominated over boys (1.4:1). For endocrine abnormality, 14 patients had isolated precocious puberty, five patients had isolated Cushing syndrome, 10 patients had precocious puberty plus Cushing syndrome, and five patients did not have any symptoms. The most frequent findings in laboratory tests were disturbance of the normal circadian rhythm of cortisol secretion (93.8%), followed by elevated serum level of testosterone (89.7%). Only 3.8% of ultrasound diagnosis and 12.1% of computed tomography (CT) diagnosis were consistent with pathologic diagnosis. CONCLUSION: Different from those in adult, the most frequent presentation in children with ACTs is peripheral precocious puberty with or without Cushing syndrome, and isolated Cushing syndrome. Few present with non-functional local mass. Laboratory tests usually reveal the discordantly elevated serum levels of sexual corticosteroid hormones, change of diurnal rhythm of cortisol or increase of morning cortisol. The differentiation of malignant from benign tumor cannot merely depend on imaging. Final diagnosis relies on comprehensive evaluation of clinical manifestations, laboratory data, imaging and pathology.

Stanozolol regulates proliferation of growth plate chondrocytes via activation of ERalpha in GnRHa-treated adolescent rats.

Improving the final adult height is one of the most important aims for treatment of central precocious puberty. Stanozolol (ST) is a synthetic derivative of androgen. In this study, we investigated the effects and the mechanisms of ST on the proliferation of growth plate chondrocytes isolated from adolescent rats treated with gonadotropin-releasing hormone analogue (GnRHa). Treatment with ST resulted in time- and concentration-dependent effects on proliferation as determined by MTT and proliferating cell nuclear antigen (PCNA) assays. Western blotting showed that ST increased the phosphorylation level of the estrogen receptor alpha (ERalpha), but not the androgen receptor (AR). Pharmacological inhibition of ERalpha and mitogen-activated protein kinase (MAPK) attenuated the effects of ST on the proliferation of growth plate chondrocytes. A molecular dynamics simulation showed hydrophobic interactions between ST and ERalpha. These results suggested that ERalpha, but not AR, partially mediates the ST-driven proliferation of growth plate chondrocytes, and that multiple pathways may be involved in the mechanism of action of ST.

[Identification of a novel mutation of GALNS gene from a Chinese pedigree with mucopolysaccharidosis type IV A].

OBJECTIVE: To study the molecular genetic mechanism of mucopolysaccharidosis type IV A(MPS IV A), and reveal the relationship between the genotype and phenotype, and provide a basis for prenatal gene diagnosis in the future. METHODS: A preliminary diagnosis was made by qualitative detection of urinary glycosaminoglycans of the suspected MPS IV A proband. Then, mutation detection was performed on the proband and her family members with PCR and direct sequencing of the PCR products. After a novel c.1567T to G mutation was detected, Xsp I restriction enzyme digestion and amplification refractory mutation system (ARMS) fast specific identification were established to analyze the sequences of exon 14 in GALNS gene, including 110 randomly selected healthy controls, the proband and other pedigree members. At the same time, bioinformatic approaches for protein secondary, tertiary structure prediction were applied to identify the novel pathologic mutation. RESULTS: The proband's urine GAGs test was a weak positive(± ), and a c.1567T to G heterozygous termination codon mutation in exon 14 and a c.374C to T heterozygous missense mutation in exon 4 were found. The proband was compound heterozygous of the two mutations, so was her younger sister. Her mother was a carrier with only a c.1567T to G heterozygous mutation in exon 14. Her father had a heterozygous mutation of c.374C to T in exon 4. After Xsp I restriction enzyme digestion, healthy controls had three bands including 28 bp, 120 bp and 399 bp, while the proband and her mother had four bands consisting of 28 bp, 120 bp, 148 bp and 399 bp. For amplification by ARMS specific primers, it was negative for the controls, while it was positive for the proband and the carrier. The results of protein secondary and tertiary structure prediction showed that the c.1567T to G mutation located in the stop codon, resulted in stop codon (TAG) changing to glutamic acid (GAG), with the peptide chain extending 92 amino acid residues, and secondary and tertiary protein structure change, which were not found in the controls. The result of enzyme assay showed that the activity of GALNS enzyme in the affected child was 8.3 nmol/17h/mg pr, which was obviously lower than the normal value (the normal range is 41.9-92.1 nmol/17h/mg pr). CONCLUSION: These results illustrate that the c.1567 T to G is a novel pathologic mutation, which is the main cause of the disease in this family.

Etiology of primary adrenal insufficiency in children: a 29-year single-center experience.

Background Primary adrenal insufficiency (PAI) in children is a rare condition and potentially lethal. The clinical characteristics are non-specific. It may be manifested as a chronic condition or crisis. The etiologies of PAI in children are different from the adult population. Therefore, diagnostic investigation becomes challenging. Methods A retrospective study was conducted at The First Affiliated Sun Yat Sen University Pediatric Endocrine unit between September 1989 and July 2016. Results A total of 434 patients (237 males, 197 females) were identified as having PAI. Congenital adrenal hyperplasia (CAH) was the most frequent etiology (83.4%, n = 362, male:female = 174:188), of which 351 (97.2%) were 21-hydroxylase deficiency (21-OH) CAH. Non-CAH etiology accounted for 11.3% (n = 49, male:female = 47:2), of which 46 (93.9%) were of non-autoimmune. The etiologies of the 49 cases were adrenoleukodystrophy (ALD; n = 22), X-linked adrenal hypoplasia congenital (X-AHC; n = 20), autoimmune polyglandular syndrome (APS; n = 3), triple A syndrome (n = 2), steroidogenic factor 1 (SF-1) gene mutation (n = 1) and adrenalectomy (n = 1). The etiology was not identified for 23 patients (5.3%, male:female =16:7). Clinical symptoms were in accordance with the incidence of genital ambiguity (42.6%), digestive symptoms (vomiting and diarrhea) (35.5%), failure to thrive (26.5%), gonadal-associated symptom (premature puberty, sexual infantilism and amenorrhea) (21.2%), hyperpigmentation (9.7%), adrenal crisis (AC; 4.1%), neurological symptoms (3.2%), fatigue (2.5%) and prolonged jaundice (2.1%). Through physical examination, 58.5% were found to have hyperpigmentation. Conclusions This study spanned 29 years at our institution. The etiology of PAI in children was mostly of congenital forms, which exhibits a wide spectrum of clinical characteristics. For etiological diagnosis, chromosomal karyotyping is recommended for female phenotype patients.

Mutation analysis and pathogenicity identification of Mucopolysaccharidosis type IVA in 8 south China families.

BACKGROUND: Mucopolysaccharidosis type IVA (MPS IVA) is a rare autosomal recessive lysosomal storage disorder caused by GALNS gene mutation. The aim of our study is to detect pathogenic variants for patients suspected of MPS IVA and set the base for subsequent prenatal diagnosis and preimplantation genetic diagnosis. METHODS: In our study, 9 MPS IVA patients from south China families were investigated. Urine glycosaminoglycans (GAGS) screening was used as an initial method. For patients with abnormal result, all 14 exons and intron-exon junctions of the GALNS gene were sequenced after amplification from genomic DNA. The pathogenicity of novel mutations were analyzed with molecular genetics, bioinformatics and structure modeling in light of clinical manifestations and biochemical results. RESULTS: Among 12 mutations detected, direct sequencing found 3 novel mutations (c.686A>C, p.Y229S; c.1498G>T, p.G500C; c.278T>C, p.I93T). The pathogenicity of these novel mutations was illustrated by correlating clinical symptoms with pedigree analysis and bioinformatics analysis. CONCLUSION: The detection and variant analysis are essential for accurate diagnosis of MPS IVA patients. Our results enrich GALNS gene mutation spectrum of Chinese population. This information has important clinical value for molecular diagnosis and genetic counseling of patients with this disease.

Postreceptor crosstalk on PI3K/Akt between GH and insulin in non-catch-up growth rats born small for gestational age.

BACKGROUND/AIMS: Children born small for gestational age (SGA) are at increased risk for short stature and type 2 diabetes mellitus as a result of growth hormone (GH) resistance and insulin resistance. The mechanisms of multiple hormone resistance remain unclear. This study was designed to investigate the relationship between GH resistance and insulin resistance in non-catch-up growth (NCU-SGA) rats, and how their signaling pathways are related based on their crosstalk on the insulin receptor substrate-1 phosphatidylinositol 3'-kinase (IRS-1-PI3K) pathway. METHODS: NCU-SGA rat model was developed by restricting prenatal food intake in pregnant dams. Activated levels of IRS-1 and Akt in liver protein extracts were compared between NCU-SGA and age- and sex-matched controls born appropriate for gestational age rats at baseline, after insulin stimulation, and after pretreatment with AG490 (GH-JAK2 pathway inhibitor) followed by insulin stimulation. RESULTS: GH secretion was positively related to markedly increased insulin levels in NCU-SGA rats. There was no difference of IRS-1 phosphorylation in response to insulin between two groups, however, insulin-stimulated Akt phosphorylation was attenuated in NCU-SGA rats compared to appropriate for gestational age rats. Pretreatment with AG490 restored the Akt response to insulin demonstrated by significantly increased Akt phosphorylation. CONCLUSION: GH plays a role in inducing insulin resistance via signaling crosstalk with insulin at the level of PI3K/Akt in NCU-SGA rats.

An analysis of predictive factors for the conversion from premature thelarche into complete central precocious puberty.

AIM: To determine the predictive factors for the conversion of premature thelarche (PT) into complete central precocious puberty (CCPP) in girls. DESIGN: Prospective. METHODS: One hundred and fifty-one girls with PT referred consecutively for evaluation of clinical, laboratory, and ultrasound data. RESULTS: Twenty-one and a half percent of girls with PT converted into CCPP at a chronological age of 7.1 +/- 0.7 years and bone age of 9.0 +/- 1.1 years. Using logistic regression analysis, longitudinal diameter of uterus (OR = 1.215), Tanner breast stage at the time of first physical examination (OR = 3.334) and regression of breast development (OR = 3.921) were the most significant variables predicting the conversion from PT into CCPP. Compared with the non-converted group, the converted groups had larger breast size at the time of diagnosis (z = 2.077, p = 0.038). A total of 69.5% (105/151) of patients experienced complete regression of breast development, 13.2% (14/105) of whom converted into CCPP; 21.5% (31/151) of patients had recurrent breast development, 32.3% (10/31) of whom converted into CCPP; 10% (15/151) of patients had constant breast development, 56.7% (7/15) of whom converted into CCPP, with the highest rate among the three breast development categories (chi2 = 12.23, p = 0.002). CONCLUSION: PT is not often a self-limited condition and may sometimes convert into CCPP. The predictive factors for conversion were related to estrogen exposure including longitudinal diameter of the uterus, Tanner breast stage at the first consultation and the regressive categories of breast development.