Summary

Maturity-onset diabetes of the young (MODY) is a group of monogenic forms of diabetes mellitus characterized by early-onset diabetes with dominant inheritance of beta-cell dysfunction. There are few reports of the coinheritance of glucokinase (GCK) and hepatocyte nuclear factor 1 alpha gene (HNF1A) variants underlying MODY in patients. Herein, we describe a case involving combinations of monoallelic GCK and HNF1A variants associated with MODY. A 10-year-old Japanese girl with a three-generation family history of diabetes without obesity showed high levels of urinary glucose during a school screening test. Her glucose metabolism profile revealed 124 mg/dL of fasting glucose, 6.9% glycated hemoglobin (HbA1c), and 2.78 ng/mL of C-peptide immunoreactivity levels. In a 75-g oral glucose tolerance test, her base glucose, peak glucose, insulin resistance, and homeostasis model assessment of beta cell function levels were 124 mg/dL, 210 mg/dL (120 min), 1.71, and 33%, respectively. Based on the clinical phenotype of GCK-MODY, alimentary and exercise therapy without oral hypoglycemic agents were used to maintain her fasting glucose and HbA1c levels. We explored the coinheritance of MODY with GCK and HNF1A variants in this and past cases and found that careful clinical follow-up is required to firmly establish phenotypic features. Moreover, the accumulation of data on genetically confirmed MODY associated with the coinheritance of GCK and HNF1A variants will be useful for understanding genotype–phenotype correlations.

Learning points

• MODY is a group of monogenic forms of diabetes mellitus characterized by early-onset diabetes with the dominant inheritance of beta-cell dysfunction.

• MODY2 and MODY3 caused by heterozygous loss-of-function variants in the glucokinase (GCK) and hepatocyte nuclear factor 1 alpha (HNF1A) genes, respectively, are the most common forms of the disease.

• Few cases of MODY have previously been reported as being associated with the coinheritance of GCK and HNF1A variants.

• Careful clinical follow-up is required to firmly establish phenotypic features in the coinheritance of MODY with GCK and HNF1A variants.

• The accumulation of data on genetically confirmed MODY associated with the coinheritance of GCK and HNF1A variants will be useful for understanding genotype–phenotype correlations.

Summary

At the end of the 19th century, an 18-year-old lady gave birth to a well-proportioned, though very small, son. After delivery, the mother developed a full-grown beard, whereas the son always remained of small stature. The mother developed diabetes mellitus and died, aged 59, from a complicated severe cold. The son died at the age of 91 because of chronic kidney disease. The differential diagnosis in the son is isolated growth hormone deficiency. The mother might have suffered luteoma of pregnancy, polycystic ovary syndrome (PCOS), or Sertoli–Leydig cell tumor(s). The two cases are apparently coincidental/not related in pathophysiology.

Learning points

• Hirsutism occurring directly postpartum can have several causes.

• Patients with isolated growth hormone deficiency can live a long life without the substitution of growth hormone.

• Coincidence does not necessarily imply correlation.

• In the past, patients with endocrine disorders like severe hirsutism or small stature were employed at circuses and fairs to entertain the audience as curiosities.

Summary

A 6.6-year-old female presented to endocrinology with precocious puberty for evaluation and management. Workup was initiated, and a diagnosis of central precocious puberty was confirmed. A decision was made to initiate pubertal blockade using gonadotropin-releasing hormone agonist (GnRHa) therapy with depot leuprolide acetate injections every 3 months. The patient received the first depot leuprolide acetate injection in the right ventrogluteal area. Six hours following the injection, the patient was reported to be inconsolable in pain, which was localized to the right hip site of the earlier injection and associated with a refusal to ambulate. The pain and discomfort continued to progress over the next 24 h despite an alternating regimen of Tylenol and ibuprofen prompting admission to the emergency department. Vital signs demonstrated a low-grade fever and elevated C-reactive protein. An ultrasound of the right hip demonstrated fluid accumulation within the joint. Over the next week, the patient was unable to walk independently and required assistance for activities of daily living. By 2 weeks after the injection, the pain began to remit, and the patient resumed activities of daily living. Following consultation with allergy, a decision was made to continue GnRHa suppressive therapy with an alternative analog (Triptodur). The patient tolerated subsequent treatment without reaction.

Learning points

• Although gonadotropin-releasing hormone agonists (GnRHa) have a generally good safety profile, there is a history of both local and systemic hypersensitivity reactions associated with their use.

• Despite the long-acting formulation of depot leuprolide acetate, the systemic reaction in this case appears to be self-limited.

• Discontinuation of therapy or a change to an alternative formulation of GnRHa analog should be considered based on the need for therapy versus the potential risk of rechallenge.

Summary

X-linked hypophosphatemic rickets (XLH), the most prevalent form of inherited hypophosphatemic rickets, is caused by loss-of-function mutations in the gene encoding phosphate-regulating endopeptidase homolog, X-linked (PHEX). This case series presents 14 cases of XLH from Gulf Cooperation Council (GCC) countries. The patients’ medical history, biochemical and radiological investigative findings, as well as treatment responses and side effects from both conventional and burosumab therapy, are described. Cases were aged 2–40 years at diagnosis. There were two male cases and 12 female cases. All cases were treated with conventional therapy which resulted in a lack of improvement in or worsening of the clinical signs and symptoms of rickets or biochemical parameters. Side effects of conventional therapy included nausea, diarrhea, abdominal pain, nephrocalcinosis, and hyperparathyroidism, which affected the patients’ quality of life and adherence to treatment. In the 10 patients treated with burosumab, there was a marked improvement in the biochemical markers of rickets, with a mean increase in serum phosphate of +0.56 mmol/L and tubular maximum phosphate reabsorption (TmP) to glomerular filtration rate (GFR) ratio (TmP/GFR) of +0.39 mmol/L at 12 months compared to baseline. Furthermore, a mean decrease in serum alkaline phosphatase (ALP) of −80.80 IU/L and parathyroid hormone (PTH) of −63.61 pmol/L at 12 months compared to baseline was observed in these patients. Additionally, patients treated with burosumab reported reduced pain, muscle weakness, and fatigue as well as the ability to lead more physically active lives with no significant side effects of treatment.

Learning points

• Conventional therapy resulted in a suboptimal response, with a lack of improvement of clinical signs and symptoms.

• Side effects of conventional therapy included nausea, diarrhea, abdominal pain, nephrocalcinosis, and hyperparathyroidism, which affected the patients’ quality of life and adherence to treatment.

• Burosumab demonstrated marked improvements in the biochemical markers of rickets, in addition to reducing pain, muscle weakness, and fatigue.

• There were no significant side effects associated with burosumab therapy.

Summary

Iodine nutrition is a growing issue within the USA due to newer trends of non-iodized salts. There are no recent reviews looking at the current state of iodine deficiency-induced hypothyroidism in children in the USA. We performed a retrospective chart review at our tertiary pediatric endocrine clinic; four met the diagnostic criteria for iodine deficiency defined by a low urine iodine level. We further characterized severity of disease, risk factors, goiter, thyroid labs and antibodies. All cases had significant goiter and were diagnosed within the last 2 years. One case had iodine deficiency due to no iodized salt intake along with concurrent diagnosis of developmental delay and multiple food allergies, while others involved the use of non-iodized salts. Two cases had iodine deficiency along with autoimmunity. It is critical to obtain a dietary history for all patients who present with goiter and/or hypothyroidism. There may be a need to consider reevaluating current preventative measures for iodine deficiency, especially for certain vulnerable populations such as children who do not consume iodized salt.

Learning points

• In recent decades, iodine nutrition has become a growing concern due to changing dietary patterns and food manufacturing practices.

• A dietary history is crucial to obtain in children presenting with hypothyroidism and goiter, especially in children with restrictive diets due to behavioral concerns, developmental delays, or multiple food allergies.

• Of the 12 different types of salts commercially available, only table salt contains iodine in an appropriate amount; thus, individuals using specialty salts can develop mild to moderate iodine deficiency-related thyroid disease.

Summary

Thyroid cancer is one of the most common manifestations of Cowden syndrome, yet the syndrome is rare. The incidence of Cowden syndrome is 1 in 200,000. The diagnosis can be made clinically when patients present with a combination of symptoms such as mucocutaneous lesions with a strong personal or family history of thyroid, breast, endometrial, and colorectal cancer. A high index of suspicion is required to provide a clinical diagnosis utilizing major and minor criteria. Once a clinical diagnosis is made, genetic testing for a PTEN mutation, a tumor suppressor gene, is recommended. Cancer surveillance should be performed for those with positive genetic testing as well as those with negative genetic testing who still meet clinical diagnostic criteria. We present two cases of Cowden syndrome: one case involving an increasing number of thyroid nodules in a patient with known Cowden syndrome and another patient with a strong family history of cancer, personal history of follicular thyroid cancer, and numerous colonic polyps on screening colonoscopy. These cases demonstrate how early diagnosis of Cowden syndrome can help detect early cancer in both the patient and affected relatives.

Learning points

• Diagnosing Cowden syndrome helps pre-risk stratification for early cancer screening.

• The diagnosis of Cowden syndrome can be made with a combination of major and minor criteria: any two major criteria with or without a minor criterion; one major and one minor criterion; or three minor criteria.

• Patients who meet the diagnostic criteria for Cowden syndrome should undergo genetic screening.

Summary

Dumping syndrome is a rare but potentially serious condition that causes inappropriate postprandial hyperinsulinemia leading to hypoglycemia in children following gastrointestinal surgeries. While dietary modifications are often the first line of treatment, severe cases may require pharmacological intervention to prevent severe hypoglycemia. We present a case of successful treatment of dumping syndrome with diazoxide. A 2-month-old infant with left hypoplastic heart syndrome who underwent single ventricle palliation pathway and developed feeding intolerance that required Nissen fundoplication. Postprandial hypoglycemia was detected following the procedure, with glucose level down to 12 mg/dL, and the diagnosis of dumping syndrome was established. The patient was successfully managed with diazoxide, which effectively resolved postprandial hypoglycemia without any major adverse events. The patient was eventfully weaned off the medication at the age of 5 months. This case highlights the potential role of diazoxide in the management of pediatric patients with postprandial hyperinsulinemic hypoglycemia secondary to dumping syndrome.

Learning points

• Dumping syndrome is a possible complication of gastrointestinal surgeries and should be suspected in children with abnormal glucose levels.

• Postprandial hyperglycemia should be monitored closely for significant subsequent hypoglycemia.

• Diazoxide might be considered as part of the treatment plan for dumping syndrome.

Summary

Pancreatic dysgenesis (PD) is a rare congenital disease, with less than 100 cases reported in the literature. In most cases, patients are asymptomatic and the diagnosis is made incidentally. In this report, we present the case of two brothers with a history of intrauterine growth retardation, low birth weight, hyperglycemia, and poor weight gain. The diagnosis of PD and neonatal diabetes mellitus was made by an interdisciplinary team composed of an endocrinologist, a gastroenterologist, and a geneticist. Once the diagnosis was made, treatment with an insulin pump, pancreatic enzyme replacement therapy, and supplementation with fat-soluble vitamins was decided. The use of the insulin infusion pump facilitated the outpatient treatment of both patients.

Learning points

• Pancreatic dysgenesis is a relatively rare congenital anomaly; most of the time, patients are asymptomatic and are diagnosed incidentally.

• The diagnosis of pancreatic dysgenesis and neonatal diabetes mellitus should be made with an interdisciplinary team.

• Due to its flexibility, the use of an insulin infusion pump facilitated the management of these two patients.

Summary

The etiology of foot drop is diverse from various diseases to mechanic injuries and includes neuropathy of the peroneal nerve. Peroneal neuropathy might also be one of the forms of diabetic neuropathy, very rarely reported as the first sign of diabetes. We describe three cases of children with newly diagnosed type 1 diabetes (TID) who developed unilateral peroneal nerve palsies and tibial nerve palsies, presenting clinically as a foot drop. In two of our cases, the symptoms of foot drop occurred shortly after starting treatment for severe diabetes ketoacidosis. In the third patient, food drop was a reason for the initial medical consultation, but eventually, TID was diagnosed. The presented cases highlight that neuropathy can be observed not only as a chronic complication of T1D, but it can also appear at the time of disease manifestation. The incorrect position of the lower limb during a keto coma may contribute to the development of neuropathy.

Learning points

• Neuropathy can be observed not only as a chronic complication of type 1 diabetes (T1D), but it can also appear at the time of disease manifestation.

• The incorrect position of the lower limb causing external pressure during a keto coma may contribute to the development of neuropathy.

• It is important to examine the glycemia in patients with acute peroneal neuropathy, as this kind of peripheral neuropathy can be associated with newly diagnosed T1D. Normalization of glycemia might lead to rapid neuronal recovery.

Summary

Rare patients who have both thyroid-stimulating hormone (TSH) receptor-stimulating and -blocking antibodies can develop ‘pendulum swinging’ thyroid dysfunction. A 9-year-old girl with Down syndrome was treated with carbimazole for Graves’ disease. After 2 years of treatment, she became profoundly biochemically hypothyroid, and this persisted after carbimazole was discontinued. Low-dose L-thyroxine was commenced. This was subsequently also discontinued as biochemical hyperthyroidism developed. TSH receptor antibody bioassay identified both TSH receptor-stimulating and -blocking antibodies. Mild hyperthyroidism persisted and while consultations regarding definitive treatment were ongoing, medication was not recommenced. Thyroid function normalised spontaneously and she has remained euthyroid for the past 3 years. Previous reports have advised definitive treatment; however, our patient developed spontaneous remission which has been prolonged and definitive therapies have been avoided. It is not yet known how commonly this particular phenomenon occurs.

Learning points

• Rare patients who have both TSH receptor-stimulating and -blocking antibodies can switch between hyperthyroidism and hypothyroidism or vice versa during treatment with antithyroid drugs or thyroxine.

• Metamorphic thyroid autoimmunity is more common in Down syndrome.

• Switching between hyperthyroidism and hypothyroidism and back again is less commonly reported.

• Definitive treatment such as radioactive iodine or thyroidectomy are usually recommended.

• Prolonged remission was achieved off all medication, without recourse to definitive treatments.