High morbidity and mortality in children with untreated congenital deficiency of leptin or its receptor.

The long-term clinical outcomes of severe obesity due to leptin signaling deficiency are unknown. We carry out a retrospective cross-sectional investigation of a large cohort of children with leptin (LEP), LEP receptor (LEPR), or melanocortin 4 receptor (MC4R) deficiency (n = 145) to evaluate the progression of the disease. The affected individuals undergo physical, clinical, and metabolic evaluations. We report a very high mortality in children with LEP (26%) or LEPR deficiency (9%), mainly due to severe pulmonary and gastrointestinal infections. In addition, 40% of surviving children with LEP or LEPR deficiency experience life-threatening episodes of lung or gastrointestinal infections. Although precision drugs are currently available for LEP and LEPR deficiencies, as yet, they are not accessible in Pakistan. An appreciation of the severe impact of LEP or LEPR deficiency on morbidity and early mortality, educational attainment, and the attendant stigmatization should spur efforts to deliver the available life-saving drugs to these children as a matter of urgency.

Positive effect of leptin substitution on mood and behaviour in patients with congenital leptin deficiency.

BACKGROUND: States of starvation are characterized by reduced physical activity and social withdrawal. This has been suggested to be mediated at least in part via reduced leptin concentrations. OBJECTIVE: We therefore aimed to ascertain if leptin substitution in patients with congenital leptin deficiency (CLD) can improve physical activity and mood. METHODS: Seven patients with CLD were filmed prior to and after short- and long-term substitution (2-21 days; 3-4 months) in a play situation. Six independent, blinded investigators ranked each video according to specifically developed scales concerning motor activity, social interaction, emotionality, and mood with higher scores representing improvements. RESULTS: Short term metreleptin substitution significantly increased mean total score from 17.7 ± 4.1 to 22.6 ± 6.6 (p = 0.039), and mean scores for motor activity (4.1 ± 1.1 to 5.1 ± 1.5, p = 0.023) and social interaction (4.6 ± 1.1 to 6.2 ± 1.7, p = 0.016). After long term substitution means of all four single scales and of total score were even higher than at short-term follow-up. During a treatment pause of 3 months in two children, all four scale scores fell below substitution levels and rose again after restart. CONCLUSIONS: Metreleptin substitution improved indices of physical activity and psychological wellbeing in patients with CLD. This suggests that reduced leptin concentrations might be in part responsible for emotional and behavioural changes seen during starvation.

Biallelic Mutations in P4HTM Cause Syndromic Obesity.

We previously demonstrated that 50% of children with obesity from consanguineous families from Pakistan carry pathogenic variants in known monogenic obesity genes. Here, we have discovered a novel monogenetic recessive form of severe childhood obesity using an in-house computational staged approach. The analysis included whole-exome sequencing data of 366 children with severe obesity, 1,000 individuals of the Pakistan Risk of Myocardial Infarction Study (PROMIS) study, and 200,000 participants of the UK Biobank to prioritize genes harboring rare homozygous variants with putative effect on human obesity. We identified five rare or novel homozygous missense mutations predicted deleterious in five consanguineous families in P4HTM encoding prolyl 4-hydroxylase transmembrane (P4H-TM). We further found two additional homozygous missense mutations in children with severe obesity of Indian and Moroccan origin. Molecular dynamics simulation suggested that these mutations destabilized the active conformation of the substrate binding domain. Most carriers also presented with hypotonia, cognitive impairment, and/or developmental delay. Three of the five probands died of pneumonia during the first 2 years of the follow-up. P4HTM deficiency is a novel form of syndromic obesity, affecting 1.5% of our children with obesity associated with high mortality. P4H-TM is a hypoxia-inducible factor that is necessary for survival and adaptation under oxygen deprivation, but the role of this pathway in energy homeostasis and obesity pathophysiology remains to be elucidated.

Management challenges of Rabson Mendenhall syndrome in a resource limited country: a case report.

OBJECTIVES: Rabson Mendenhall syndrome  (RMS) is a rare form of insulin resistance syndrome caused by insulin receptor mutation. In term of severity, it lies at an intermediate point on spectrum of insulin resistance with Donohue syndrome flanking the severe and Type A insulin resistance at the mild end. We are reporting a 3.5-month-old boy with RMS along with its management challenges in a resource limited country. CASE PRESENTATION: An infant presented at 3.5-month of an age with failure to thrive and fluctuating blood glucose level (hyperglycaemia and hypoglycaemia) along with clinical features of insulin resistance. He was found to have raised HbA1C, high insulin and C peptide level and a homozygous mutation in INSR gene c.1049C>T, (p.Ser350 Leu) confirming the diagnosis of RMS. He was managed with long-acting insulin (Detemir) along with frequent feeding. CONCLUSIONS: RMS in resource limited countries could be managed with frequent feeding along with insulin. Early diagnosis and management can improve long term outcome.

Precocious puberty: The clinical profile and the etiological classification of children presented at a tertiary care children's hospital.

Objectives: To determine the clinical spectrum and underlying etiologies of children presented with precocious puberty at The Children's Hospital &The Institute of Child health, Lahore. Methods: It is a retrospective review of all the children presented with precocious puberty over one year, from January 2015 to December 2015; at the department of Paediatric Endocrinology & Diabetes, The Children's Hospital & The Institute of Child Health, Lahore. Results: Total 43 cases of precocious puberty (PP), with 26 females were reported in one year. Central precocious puberty (CPP) constituted 55.8% (24/43) and was found to be more prevalent in female (22/24). In 20/24 cases (83.3%) of central precocious puberty underlying etiology was idiopathic. Peripheral precocious puberty was found in 19/43 cases (44.1%) with male predominance (15/19). Congenital adrenal hyperplasia was the most frequent (12/19) underlying cause of peripheral precocious puberty in our cohort. Conclusion: Precocious puberty could be a manifestation of underlying serious medical condition. It should be thoroughly evaluated with the aim to diagnose the underlying pathology and to treat them promptly.

Genetic Causes of Severe Childhood Obesity: A Remarkably High Prevalence in an Inbred Population of Pakistan.

Monogenic forms of obesity have been identified in ≤10% of severely obese European patients. However, the overall spectrum of deleterious variants (point mutations and structural variants) responsible for childhood severe obesity remains elusive. In this study, we genetically screened 225 severely obese children from consanguineous Pakistani families through a combination of techniques, including an in-house-developed augmented whole-exome sequencing method (CoDE-seq) that enables simultaneous detection of whole-exome copy number variations (CNVs) and point mutations in coding regions. We identified 110 (49%) probands carrying 55 different pathogenic point mutations and CNVs in 13 genes/loci responsible for nonsyndromic and syndromic monofactorial obesity. CoDE-seq also identified 28 rare or novel CNVs associated with intellectual disability in 22 additional obese subjects (10%). Additionally, we highlight variants in candidate genes for obesity warranting further investigation. Altogether, 59% of cases in the studied cohort are likely to have a discrete genetic cause, with 13% of these as a result of CNVs, demonstrating a remarkably higher prevalence of monofactorial obesity than hitherto reported and a plausible overlapping of obesity and intellectual disabilities in several cases. Finally, inbred populations with a high prevalence of obesity provide unique, genetically enriched material in the quest of new genes/variants influencing energy balance.

Leptin Is Not Essential for Obesity-Associated Hypertension.

BACKGROUND AND OBJECTIVE: Hyperleptinemia is supposed to play a causal role in the development of obesity-associated hypertension, possibly via increased sympathetic tone. Hence patients with congenital leptin deficiency should be hypotensive and their low blood pressure should increase under leptin substitution. SUBJECTS AND METHODS: To test this assumption, we examined ambulatory blood pressure, resting heart rate, Schellong test results, cold pressor test results, heart rate variability, catecholamine metabolites, and aldosterone levels in 6 patients with congenital leptin deficiency before as well as 2-7 days and 7-14 months after the start of leptin substitution. Ambulatory blood pressure was also examined in 3 patients with biallelic disease-causing variants in the leptin receptor gene. RESULTS: Contrary to our expectations, even before leptin substitution, 1 patient with biallelic leptin receptor gene variants and 4 patients with leptin deficiency had been suffering from hypertension. Short-term substitution with leptin increased blood pressure further in 3 out of 4 patients (from 127.0 ± 11.7 to 133.8 ± 10.6 mm Hg), concomitant with an increase in resting heart rate as well as in heart rate during the Schellong test in all patients (from 87.6 ± 7.7 to 99.9 ± 11.0 bpm, p = 0.031, and from 102.9 ± 13.5 to 115.6 ± 11.3 bpm, p = 0.031, respectively). Furthermore, the systolic blood pressure response during the cold pressor test increased in 4 out of 6 patients. Unexpectedly, catecholamine metabolites and aldosterone levels did not increase. After long-term leptin substitution and weight loss, the resting heart rate decreased in 4 out of 6 patients compared to baseline, and in all patients below the heart rate seen immediately after the start of therapy (from 99.9 ± 11.0 to 81.7 ± 5.4 bpm; p = 0.031). CONCLUSIONS: These results show that obesity-associated hypertension does not depend on the presence of leptin. However, short-term leptin substitution can increase the blood pressure and heart rate in obese humans with leptin deficiency, indicating that leptin plays at least an additive role in obesity-associated hypertension. The mechanisms behind this are not clear but might include an increase in regional sympathetic tone.

Ambiguous genitalia: An overview of 7 years experience at the Children's Hospital & Institute of Child Health, Lahore, Pakistan.

OBJECTIVE: To determine the classification and etiological diagnosis of children presented with ambiguous genitalia/atypical genitalia according to the newer classification system of Disorder of Sex Development (DSD). METHODS: This observational, cross-sectional study was conducted at the Department of Pediatric Endocrinology and Diabetes at The Children's Hospital &Institute of Child Health, Lahore from January, 2007 to December; 2014. Files of all the children with ambiguous genitalia were retrospectively analyzed and relevant data was retrieved. All the information was recorded on predesigned proforma and analyzed accordingly. RESULTS: A total of 300 cases of ambiguous genitalia classified according to the new DSD classification. 46, XX DSD were 54.3% (n=163), 46, XY DSD were 43.7% (n=131), sex chromosome DSD were 2% (n=6). Among 46, XX DSD cases, the most common cause was congenital adrenal hyperplasia (97%, n=158). However, in 46, XY DSD partial androgen insensitivity/5α-reductase deficiency (62%. n=81) constituted the most commonest disorder. Other causes of 46XY DSD include testosterone synthesis defect(23%), congenital adrenal hyperplasia (CAH,12%), testis regression syndrome (1.5%) and persistent mullerian duct syndrome (PMDS,1.5%). Sex chromosome disorder constituted one case of iso-chromosome X turner syndrome, mixed gonadal dysgenesis (n=3), ovotesticular DSD/chimerism (n=2). CONCLUSION: Ambiguous genitalia have varied etiologies, 46; XXDSD found being the commonest of all, showing predominance of CAH especially salt loosing type. The early detection and prompt treatment of cases of ambiguous genitalia plays a pivotal role in the management of acute life threatening condition and gender assignment.

Congenital heart disease and thyroid dysfunction in Down syndrome reported at Children`s Hospital, Lahore, Pakistan.

Yaqoob M, Manzoor J, Hyder SN, Sadiq M. Congenital heart disease and thyroid dysfunction in Down syndrome reported at Children`s Hospital, Lahore, Pakistan. Turk J Pediatr 2019; 61: 915-924. Down syndrome is one of the main causes of intellectual disability in children. It occurs in every community and ethnic group. Several co-morbid conditions are associated with this syndrome. The present study was conducted to determine the frequency of congenital heart disease and thyroid dysfunction in a group of children affected with this genetic disorder. It was a record based retrospective study. A child having specific clinical features and chromosomal analysis showing an extra chromosome 21 was diagnosed as having Down syndrome. Diagnosis of congenital heart disease was based upon results of echocardiography. Thyroid dysfunction was diagnosed when either or both tetraiodothyronine and thyroid-stimulating hormone serum levels were abnormal. Three hundred and fifty cases were enrolled in the study according to the preset criteria for Down syndrome. Two hundred and ten (60%) were males and 140 (40%) females showing male to female ratio as 1.5 to 1. Majority of the children (55.1%) presented between 7 months and 24 months of age. Congenital heart defects were found in 41.8% of the cases. Ventricular septal defect was the most common, 41%. Thyroid dysfunction was found in 22% (n=60) of the cases of which 5.9% (n=16) had hypothyroidism. In conclusion, the frequency of congenital heart disease and thyroid dysfunction in Down syndrome children is high. Early referral of these children to tertiary health care facilities is emphasized as timely detection and management of these comorbid conditions will help in reducing the morbidity and mortality in this group of children.

Loss-of-function mutations in ADCY3 cause monogenic severe obesity.

Study of monogenic forms of obesity has demonstrated the pivotal role of the central leptin-melanocortin pathway in controlling energy balance, appetite and body weight 1 . The majority of loss-of-function mutations (mostly recessive or co-dominant) have been identified in genes that are directly involved in leptin-melanocortin signaling. These genes, however, only explain obesity in <5% of cases, predominantly from outbred populations 2 . We previously showed that, in a consanguineous population in Pakistan, recessive mutations in known obesity-related genes explain ~30% of cases with severe obesity3-5. These data suggested that new monogenic forms of obesity could also be identified in this population. Here we identify and functionally characterize homozygous mutations in the ADCY3 gene encoding adenylate cyclase 3 in children with severe obesity from consanguineous Pakistani families, as well as compound heterozygous mutations in a severely obese child of European-American descent. These findings highlight ADCY3 as an important mediator of energy homeostasis and an attractive pharmacological target in the treatment of obesity.

Leptin Replacement Reestablishes Brain Insulin Action in the Hypothalamus in Congenital Leptin Deficiency.

OBJECTIVE: Human obesity is associated with impaired central insulin signaling, and in very rare cases, severe obesity can be caused by congenital leptin deficiency. In such patients, leptin replacement results in substantial weight loss and improvement in peripheral metabolism. RESEARCH DESIGN AND METHODS: In a leptin-deficient patient, we investigated the impact of leptin substitution on central insulin action, as quantified by changes in neuronal activity after intranasal insulin application. This was assessed before and during the first year of metreleptin substitution. RESULTS: After only 1 year, treatment with metreleptin reestablishes brain insulin sensitivity, particularly in the hypothalamus and, to a lesser degree, in the prefrontal cortex. Results are depicted in comparison with a control group. In our patient, brain activation changes were accompanied by substantial weight loss, reduced visceral adipose tissue, reduced intrahepatic lipid content, and improved whole-body insulin sensitivity. CONCLUSIONS: Leptin replacement and weight loss improved homeostatic insulin action in the patient in question.

Paraneoplastic Cushing Syndrome Due To Wilm's Tumor.

Paraneoplastic syndromes are rare disorders that are triggered by an altered immune system response to neoplasm. Paraneoplastic syndromes may be the first or the most prominent manifestations of cancer. Wilm's tumor is the most frequent pediatric renal malignancy and usually presents with abdominal mass. Unusual presentations like acquired von Willebrand disease, sudden death due to pulmonary embolism and Cushing syndrome have been described in the literature. Cushing syndrome, as the presenting symptom of a malignant renal tumor in children, is a very rare entity. Few case reports are available in the literature exploring the option of preoperative chemotherapy as well as upfront nephrectomy. We report a rare case of paraneoplastic Cushing syndrome due to a Wilm's tumor. Based on gradual decrease of postoperative weight, blood pressure, serum adrenocorticotropic hormone, and plasma cortisol levels, along with histological confirmation of Wilm's tumor, paraneoplastic Cushing syndrome due to Wilm's tumor was confirmed.

Allgrove Syndrome: Adrenal Insufficiency with Hypertensive Encephalopathy.

Allgrove syndrome or triple-Asyndrome is a rare familial multisystem autosomal recessive disorder. It is characterised by triad of alacrima, achalasia and adrenal insufficiency due to adrenocorticotropin hormone (ACTH) resistance. If it is associated with autonomic dysfunction, it is termed as 4-Asyndrome. This syndrome is caused by a mutation in the Achalasia - Addisonism - Alacrima (AAAS) gene on chromosome 12q13 encoding the nuclear pore protein ALADIN. A5-year boy presented with history of fits and altered sensorium for one day. He also had increased pigmentation of body and persistent vomiting since six months of age. Laboratory investigations and imaging revealed alacrimia, achalasia and adrenal insufficiency due to ACTH resistance. He had episodes of hypertensive crises, for which he was thoroughly investigated and it was found to be due to autonomic instability. Based on clinical findings and investigations he was diagnosed as case of Allgrove syndrome or 4-Asyndrome with autonomic dysfunction.

Genetic variants in LEP, LEPR, and MC4R explain 30% of severe obesity in children from a consanguineous population.

OBJECTIVE: Single gene mutations leading to severe obesity have so far been identified in 3-5% cases in European populations. However, prevalence of these pathogenic mutations has not systematically been examined in specific consanguineous populations. Here we describe the incidence of obesity-associated mutations through a step-wise sequence analysis, in a cohort of 73 Pakistani children with severe obesity from consanguineous families. METHODS: Initially, all subjects were screened for mutations in coding regions of leptin (LEP) and melanocortin 4 receptor (MC4R) genes by direct sequencing. Subjects negative for mutation in these genes were screened using microdroplet PCR enrichment and NGS. Genomic structural variation was assessed by genotyping. Serum leptin, insulin, and cortisol were determined by ELISA. RESULTS: Among 73 children with severe obesity (BMI SDS > 3.0), we identified 22 probands and 5 relatives, carrying 10 different loss-of-function homozygous mutations in LEP, leptin receptor (LEPR), and MC4R genes, including 4 novel variants. Hypercortisolemia was significantly emphasized in LEP mutation carriers. CONCLUSIONS: The prevalence of pathogenic mutations in genes known to directly influence leptin-melanocortin signaling is 30% in our cohort. The results of this study emphasize the desirability of undertaking systematic and in-depth genetic analysis of cases with severe obesity in specific consanguineous populations.

Iatrogenic Cushing's syndrome in children presenting at Children's Hospital Lahore using nappy rash ointments.

OBJECTIVE: To study the characteristics of infants and children presenting with iatrogenic Cushing's Syndrome due to nappy rash ointments. METHODS: The descriptive study was conducted at the Children's Hospital, Lahore, from April to September 2013, and comprised patients presenting with cushingoid features and history of using nappy rash ointments. Patients having Cushing's Syndrome due to causes other than iatrogenic were excluded and so were those taking oral or parenteral steroids due to skin allergy, renal or respiratory disease. Demographic data, history and examination of all patients were recorded on a proforma and results were analysed using SPSS 16. RESULTS: Of the total 18 patients, 13(72%) were girls and 5(27%) were boys. Eight (44.4%) patients were younger than 6 months, 6(33.3%) were between 6 months to 1 year, while 4(22.2%) were between 12 and 18 months of age. Clobetasol alone was the most frequently used agent responsible in 13(72%) cases. Duration of use of steroid ointment was as short as 3 weeks to as much as 1 year. All the patients were using disposable diapers. Ointment was prescribed by a doctor in 5(27%) cases and self-prescribed (relative or neighbour) in 13(72%). CONCLUSIONS: Self-medication and prolonged use of potent steroid ointments are major contributors in development of iatrogenic Cushing's Syndrome in infants and children. Younger age, female gender and use of disposable diapers were other important predisposing factors.

Novel LEPR mutations in obese Pakistani children identified by PCR-based enrichment and next generation sequencing.

OBJECTIVE: Mutations in leptin receptor gene (LEPR) result in early onset extreme adiposity. However, their prevalence in different populations is not known. Indeed, LEPR screening by gold standard Sanger sequencing has been limited by its large size and the cost. One-step PCR-based targeted enrichment could be an option for rapid and cost effective molecular diagnosis of monogenic forms of obesity. METHODS: The study is based on 39 unrelated severely obese Pakistani children, previously shown to be negative for leptin (LEP) and melanocortin 4 receptor (MC4R) gene mutations, from an initial cohort of 62 probands. Patient samples were analyzed by microdroplet PCR-enrichment (RainDance technologies) targeting coding exons of 26 obesity-associated genes combined with next generation sequencing. Hormone levels were analyzed by ELISA. RESULTS: The analysis revealed two novel homozygous LEPR mutations, an essential splice site mutation in exon 15 (c.2396-1 G>T), and a nonsense mutation in exon 10 (c.1675 G>A). Both probands had high leptin levels and were phenotypically indistinguishable from age-matched leptin-deficient subjects from the same population. CONCLUSIONS: The two subjects carrying homozygous LEPR mutations, reported here for the first time in the Pakistani population, constitute 3% of the whole cohort of severely obese children (compared to 17% for LEP and 3% for MC4R).

Leptin deficiency and leptin gene mutations in obese children from Pakistan.

BACKGROUND: Congenital leptin deficiency is a rare human genetic condition clinically characterized by hyperphagia and acute weight gain usually during the first postnatal year. The worldwide data on this disorder includes only 14 cases and four pathogenic mutations have been reported in the leptin gene. STUDY OBJECTIVE: The objectives of this study were to measure serum leptin levels in obese children and to detect leptin gene mutations in those found to be leptin deficient. PATIENTS AND RESULTS: A total of 25 obese children were recruited for the study. Leptin deficiency was detected in nine of them. Leptin gene sequencing identified mutations in homozygous state in all the leptin deficient children. Two cases carried novel mutations (c.481_482delCT and c.104_106delTCA) and each of the remaining seven the previously reported frameshift mutation (c.398delG). CONCLUSION: The results suggest that leptin deficiency caused by mutations in the leptin gene may frequently be seen in obese Pakistani children from Central Punjab.