3M syndrome: Evaluating the clinical and laboratory features and the response of the growth hormone treatment: Single center experience.

INTRODUCTION & OBJECTIVE: 3 M Syndrome is a rarely encountered autosomal recessive syndrome characterized by low birth weight, severe postnatal growth deficiency, and minor dysmorphic abnormalities. 3 M-related short stature has been attributed to the resistance to growth hormone (GH) to a certain extent rather than to GH deficiency. The resistance to GH, on the other hand, has been associated with impaired protein scaffolding, transport, and p53-mediated apoptosis at the IGF-1 post-receptor pathway. In this context, the objective of this study is to evaluate the clinical, laboratory, and genetic characteristics of the patients with 3 M syndrome, detect the mutations frequently observed in these patients, and assess their response to GH treatment. MATERIAL&METHODS: The sample of this single-center study consisted of patients diagnosed with 3 M syndrome based on genetic tests between 2007 and 2021. Patients' clinic, laboratory, and genetic characteristics pertaining to the time of admission and follow-up were recorded. All patients except one underwent a growth hormone stimulation test (GHST) (Levo-dopa or insulin tolerance test). Insulin-like growth factor (IGF) generation test was performed on those with sufficient GHST results (0.1 mg/kg/day for four days). RESULTS: The median age of the patients, five females and three males, was 2.8 (0.25-8.12) years at admission. All but one patient were small for gestational age (SGA). The patient with normal birth weight was the baby of a diabetic mother. Obscurin-like 1 (OBSL1) variant was detected in all cases. The median height standard deviation score (SDS) at admission was -4.94 ((-5.63)- (-3.27)) SDS, and the median midparenteral height SDS was -1.27 SDS ((-3.1)- (0.34)). All patients were prepubertal at admission. The GHST response was sufficient in five cases. IGF generation test was performed in three cases. Seven patients received GH therapy (35-57 µg/kg/day). Five of these patients discontinued GH therapy since their growth velocity (GV) fell below normal during treatment. In addition, one case discontinued GH therapy because her IGF-1 value was>2 SDS, and another case received gonadotropin-releasing hormone (GnRH) analogs together with GH therapy. The median age and height SDS of the patients were 10.1 (1.79-18) years and -5.09 SDS ((-7.11)- (2.45)), respectively, as of the last follow-up visit. The height SDS values of the two cases that reached the final height were -7.11 SDS and -3.39 SDS. There were no side effects of GH treatment. CONCLUSION: The study findings indicated a good GV during the early stages of the long-term GH treatment administered to patients with 3 M syndrome. However, response to GH therapy decreased in the following years, and the desired improvement in height SDS could not be achieved in patients who reached their final heights. Taken together with the literature data, it has been concluded that initiating GH therapy in the prepubertal period provided better outcomes than after puberty.

Unfavorable Effects of Low-carbonhydrate Diet in a Pediatric Patient with Type 1 Diabetes Mellitus

A balanced and healthy diet is very important in type 1 diabetes mellitus (T1DM) in childhood. In addition to regulating blood glucose with diet, diet should also support optimal growth. Low-carbohydrate diet aims to provide daily energy from fats and was originally used for childhood epilepsy. We present a patient with T1DM who experienced unfavorable effects when on a low-carbohydrate diet.

Evaluation of permanent and transient congenital hypothyroidism in cases referred from National Neonatal Screening Program.

AIM: The incidence of congenital hypothyroidism (CH) has increased world-wide. Lowering cut-off in screening programs has led to an increase in the rate of transient CH. We aimed to evaluate the rates of permanent and transient CH in cases referred from the screening program and to investigate the clinical and laboratory factors which predict transient CH. METHODS: In 109 cases referred from the neonatal screening program to our hospital, from September 2015 to April 2018, 52 primarily diagnosed CH cases were prospectively evaluated. Regularly followed up, 44 CH cases were included in the study at the end of 3 years. RESULTS: 38.2 ± 1.31 weeks (w) and mean birthweight 3021.3 ± 389.6 gram (g) in the transient CH group; both were significantly lower compared to permanent CH cases with 39.06 ± 1.33 w and 3375.3 ± 425.3 g (P = 0.025, P = 0.007) respectively. Transient CH rate was found to be 50% (all hypoplastic) in the dysgenesis group and 73.3% in groups with normal and hyperplasic thyroid gland. While fT4 , thyroid-stimulating hormone, and thyroglobulin levels at diagnosis do not predict transient/permanent CH, levothyroxine (LT-4) dosage was significantly lower in the transient CH group in all years. The optimal cut-off value with highest sensitivity and specificity for LT-4 dosage as a predictive marker to differentiate transient CH from permanent CH was 2.27 µg/kg/day (P = 0.004; sensitivity: 71%, specificity: 83%) at 1st year, 1.85 µg /kg/day (P = 0.013; sensitivity: 66%, specificity: 72%) at 2nd year and 1.69 µg /kg/day at 3rd year (P < 0.0001; sensitivity: 90%, specificity: 83%). CONCLUSION: Transient CH is more frequent than expected. Our results suggest that LT-4 requirement may be a good marker for predicting transient CH, while thyroid hormone levels at the time of diagnosis do not significantly predict permanent and transient CH. Therefore, infants with CH requiring LT-4 doses <2.27 µg/kg/day at 1st year, <1.85 µg /kg/day at 2nd year may be re-evaluated earlier to discriminate transient CH rather than at 3 years of age.

Mild phenotype in two siblings with a missense GHR variant.

OBJECTIVES:  Laron syndrome (LS) is a disease caused by growth hormone receptor (GHR) defects. It is characterized by severe postnatal growth retardation and distinctive facial features. CASE PRESENTATION: In this case report, we describe the clinical and biochemical characteristics of two siblings with LS, a sister and a brother, and identify a homozygous c.344A> C (p.Asn115Thr) variant in GHR. The sister was 11 years 9 months old with a height of 127.5 cm (-3.86 SDS), and the brother was 14 years 10 months old with a height of 139 cm (-4.27 SDS). Their phenotype did not have features suggesting classical LS. CONCLUSION: In the current literature, there are three cases with the same missense variant. Our cases differ from them in clinical (higher height SDS, mild dysmorphism including a broad forehead, malar hypoplasia, prominent columella and chin, thick lips) and biochemical characteristics. Here, we present the variable expressivity in the two siblings.

Perinatal outcomes of high-dose vitamin D administration in the last trimester

In recent years, interest in the evaluation of vitamin D levels and the possible outcomes of their deficiency during pregnancy has increased. However, there is no consensus on when to start vitamin D supplementation, its duration, dosage, and the optimum level during pregnancy. The toxicity of vitamin D is as important as its deficiency. From the history of a 5-day-old male baby who was investigated for hypercalcemia, it was learned that the mother took 300,000 IU vitamin D-five ampoules/oral at 30 weeks of gestation every other day. The infant was born prematurely, postpartum bradycardia required positive pressure ventilation, and his hypercalcemia lasted approximately 4 months despite treatment. Maternal excessive and inappropriate use of vitamin D can cause preterm labor and severe hypercalcemia, which is a life-threatening complication in the neonatal period. This case is presented to draw attention to the negative effects of maternal high-dose vitamin D during pregnancy.

A case of prohormone convertase deficiency diagnosed with type 2 diabetes.

Prohormone convertase 1/3, encoded by the proprotein convertase subtilisin/kexin type 1 gene, is essential for processing prohormones; therefore, its deficiency is characterized by a deficiency of variable levels in all hormone systems. Although a case of postprandial hypoglycemia has been previously reported in the literature, prohormone convertase insufficiency with type 2 diabetes mellitus has not yet been reported. Our case, a 14-year-old girl, was referred due to excess weight gain. She was diagnosed as having type 2 diabetes mellitus based on laboratory test results. Prohormone convertase deficiency was considered due to the history of resistant diarrhea during the infancy period and her rapid weight gain. Proinsulin level was measured as >700 pmol/L(3.60-22) during diagnosis. In genetic analysis, a c.685G> T(p.V229F) homozygous mutation in the PCSK1 gene was detected and this has not been reported in relation to this disorder. In conclusion, patients with recurrent resistant diarrhea during infancy followed by rapid weight gain need to be evaluated with the diagnosis of prohormone convertase deficiency.

Is Bioavailable Vitamin D Better Than Total Vitamin D to Evaluate Vitamin D Status in Obese Children?

Introduction: Free hormones are biologically more active in target tissues. Thus, measurement of vitamin D taking into account bioavailability and free vitamin D may be preferable, especially when evidence is contradictory, as in obese children. In order to assess bioavailablity and free vitamin D, using a previously reported formula, vitamin D-binding protein (VDBP) level was measured and VDBP polymorphisms were also evaluated because of variations in binding affinity. Methods: Eighty-four obese and 78 healthy children were included. Anthropometry, calcium, phosphorus, alkaline-phosphatase, parathyroid hormone (PTH), 25 hydroxyvitamin D [25(OH)D], bioavailable-free vitamin D, and VDBP concentration and polymorphism were evaluated in the whole group. Results: Obese girls had significantly higher PTH than normal weight girls (p=0.001). Regardless of gender, obese children had significantly higher concentrations of VDBP (p=0.008) and PTH (p=0.002). When samples taken in winter were analyzed, PTH and VDBP were found to be higher and bioavailable and free vitamin D lower in the obese group. There was no difference in terms of total vitamin D between groups during the winter season. Conclusion: While total, free, and bioavailable vitamin D in the obese group was similar to the control group in autumn, free and bioavailable vitamin D in the winter was lower in the obese than the control group. In addition, PTH was higher in the obese group in both autumn and winter. Therefore, more research is needed to evaluate the variability of free and bioavailable vitamin D according to body habitus, season and the effect any differences may have.

Treatment Difficulties in Hypomagnesemia Secondary to the Transient Receptor Potential Melastatin 6 Gene: A Case Report with Novel Mutation

Hypomagnesemia is a rare cause of seizures in childhood but should be kept in mind in recurrent and intractable seizures and hypocalcemia in communities where consanguineous marriages are common. Familial hypomagnesemia with secondary hypocalcemia is a rare genetic cause of hypomagnesemia, due to variants in the transient receptor potential melastatin 6 (TRPM6) genes. Here, a three year-old boy with a novel variant in this gene and had difficulties with enteral hypomagnesemia treatment is presented. He had recurrent seizures since two years of age and was diagnosed with epilepsy and treated with multiple antiepileptic drugs. Subsequently, he was diagnosed with rickets due to severe hypocalcemia at another center. The patient was hypotonic and neurodevelopmentally poor. The most prominent laboratory finding was of hypomagnesemia with secondary hypocalcemia. The genetic analysis revealed a novel variant in the TRPM6 gene. After parental treatment of intravenous magnesium (Mg2+) sulfate and calcium, the treatment was switched to enteral Mg2+ medications, due to persistent hypomagnesemia and the gastrointestinal side-effects, different oral preparations were used. The patient was stable on an oral maintenance dose of Mg2+ oxide with borderline blood Mg2+ levels and resolution of hypocalcemia. Hypomagnesemia is one of the causes of hypocalcemia. Enteral replacement is the key treatment but the treatment should be individualized for each patient. Normalization of hypomagnesemia is not always easy and should not be the aim of the treatment.

Clinical Management in Systemic Type Pseudohypoaldosteronism Due to SCNN1B Variant and Literature Review

Systemic pseudohypoaldosteronism (PHA) is a rare, salt-wasting syndrome that is caused by inactivating variants in genes encoding epithelial sodium channel subunits. Hyponatremia, hyperkalemia, metabolic acidosis, increased aldosterone and renin levels are expected findings in PHA. Clinical management is challenging due to high dose oral replacement therapy. Furthermore, patients with systemic PHA require life-long therapy. Here we report a patient with systemic PHA due to SCNN1B variant whose hyponatremia and hyperkalemia was detected at the 24th hour of life. Hyperkalemia did not improve with conventional treatments and dialysis was required. He also developed myocarditis and hypertension in follow-up. Challenges for diagnosis and treatment in this patient are discussed herein. In addition, published evidence concerning common features of patients with SCNN1B variant are reviewed.

Dynamic thiol/disulphide homeostasis and pathogenesis of Kawasaki disease.

BACKGROUND: Kawasaki disease (KD) is an acute, self-limited, systemic vasculitis of unknown etiology. In the present study, we investigated whether there is a relationship between KD and dynamic thiol/disulphide homeostasis. METHODS: This case-control study involved KD patients and healthy controls. Plasma total, native and disulphide thiol and the disulphide/native, disulphide/total and native thiol/total thiol ratios of all patients and the control group were analyzed simultaneously. RESULTS: A total of 20 patients with KD (male/female, 12/8) and 25 age- and gender-matched healthy controls (male/female, 12/13) were evaluated. Native, total thiol and native thiol/total thiol ratio were significantly lower in KD patients than in the control group (P < 0.001). In contrast, disulphide thiol, disulphide/native thiol and disulphide/total thiol ratios were significantly higher in KD patients than control subjects (P < 0.001). In KD patients with coronary artery lesion (CAL), the native thiol and total thiol were significantly lower than in KD patients without CAL. In KD patients with CAL, the ratios of disulphide/total thiol and disulphide/native thiol were significantly higher than in those without CAL (P = 0.02 and P = 0.02, respectively), whereas the ratio of native/total thiol was significantly lower (P = 0.02). CONCLUSION: The KD patients had lower plasma thiol (native and total) and higher disulphide thiol than controls, indicating that dynamic thiol/disulphide homeostasis might be an important indicator of inflammation in KD. Alteration and shifting of thiol/disulphide homeostasis to the oxidized side are correlated with the pathogenesis of KD and CAL.