Intranasal Carbetocin Reduces Hyperphagia, Anxiousness, and Distress in Prader-Willi Syndrome: CARE-PWS Phase 3 Trial.

CONTEXT: Prader-Willi syndrome (PWS) is a rare genetic disorder characterized by endocrine and neuropsychiatric problems including hyperphagia, anxiousness, and distress. Intranasal carbetocin, an oxytocin analog, was investigated as a selective oxytocin replacement therapy. OBJECTIVE: To evaluate safety and efficacy of intranasal carbetocin in PWS. DESIGN: Randomized, double-blind, placebo-controlled phase 3 trial with long-term follow-up. SETTING: Twenty-four ambulatory clinics at academic medical centers. PARTICIPANTS: A total of 130 participants with PWS aged 7 to 18 years. INTERVENTIONS: Participants were randomized to 9.6 mg/dose carbetocin, 3.2 mg/dose carbetocin, or placebo 3 times daily during an 8-week placebo-controlled period (PCP). During a subsequent 56-week long-term follow-up period, placebo participants were randomly assigned to 9.6 mg or 3.2 mg carbetocin, with carbetocin participants continuing at their previous dose. MAIN OUTCOME MEASURES: Primary endpoints assessed change in hyperphagia (Hyperphagia Questionnaire for Clinical Trials [HQ-CT]) and obsessive-compulsive symptoms (Children's Yale-Brown Obsessive-Compulsive Scale [CY-BOCS]) during the PCP for 9.6 mg vs placebo, and the first secondary endpoints assessed these same outcomes for 3.2 mg vs placebo. Additional secondary endpoints included assessments of anxiousness and distress behaviors (PWS Anxiousness and Distress Behaviors Questionnaire [PADQ]) and clinical global impression of change (CGI-C). RESULTS: Because of onset of the COVID-19 pandemic, enrollment was stopped prematurely. The primary endpoints showed numeric improvements in both HQ-CT and CY-BOCS which were not statistically significant; however, the 3.2-mg arm showed nominally significant improvements in HQ-CT, PADQ, and CGI-C scores vs placebo. Improvements were sustained in the long-term follow-up period. The most common adverse event during the PCP was mild to moderate flushing. CONCLUSIONS: Carbetocin was well tolerated, and the 3.2-mg dose was associated with clinically meaningful improvements in hyperphagia and anxiousness and distress behaviors in participants with PWS. CLINICAL TRIALS REGISTRATION NUMBER: NCT03649477.

Prenatal Treatment of Thyroid Hormone Cell Membrane Transport Defect Caused by MCT8 Gene Mutation.

Background: Mutations of the thyroid hormone (TH)-specific cell membrane transporter, monocarboxylate transporter 8 (MCT8), produce an X-chromosome-linked syndrome of TH deficiency in the brain and excess in peripheral tissues. The clinical consequences include brain hypothyroidism causing severe psychoneuromotor abnormalities (no speech, truncal hypotonia, and spastic quadriplegia) and hypermetabolism (poor weight gain, tachycardia, and increased metabolism, associated with high serum levels of the active TH, T3). Treatment in infancy and childhood with TH analogues that reduce serum triiodothyronine (T3) corrects hypermetabolism, but has no effect on the psychoneuromotor deficits. Studies of brain from a 30-week-old MCT8-deficient embryo indicated that brain abnormalities were already present during fetal life. Methods: A carrier woman with an affected male child (MCT8 A252fs268*), pregnant with a second affected male embryo, elected to carry the pregnancy to term. We treated the fetus with weekly 500 µg intra-amniotic instillation of levothyroxine (LT4) from 18 weeks of gestation until birth at 35 weeks. Thyroxine (T4), T3, and thyrotropin (TSH) were measured in the amniotic fluid and maternal serum. Treatment after birth was continued with LT4 and propylthiouracil. Follow-up included brain magnetic resonance imaging (MRI) and neurodevelopmental evaluation, both compared with the untreated brother. Results: During intrauterine life, T4 and T3 in the amniotic fluid were maintained above threefold to twofold the baseline and TSH was suppressed by 80%, while maternal serum levels remained unchanged. At birth, the infant serum T4 was 14.5 µg/dL and TSH <0.01 mU/L compared with the average in untreated MCT8-deficient infants of 5.1 µg/ and >8 mU/L, respectively. MRI at six months of age showed near-normal brain myelination compared with much reduced in the untreated brother. Neurodevelopmental assessment showed developmental quotients in receptive language and problem-solving, and gross motor and fine motor function ranged from 12 to 25 at 31 months in the treated boy and from 1 to 7 at 58 months in the untreated brother. Conclusions: This is the first demonstration that prenatal treatment improved the neuromotor and neurocognitive function in MCT8 deficiency. Earlier treatment with TH analogues that concentrate in the fetus when given to the mother may further rescue the phenotype.

Trends in Obesity and Overweight in Oregon Children With Down Syndrome.

Background. Although obesity is a commonly discussed issue in the medical management of children with Down syndrome, there have been no large studies published on its prevalence in the United States or associations with other common comorbidities in this population. Methods. Using a database of children from a single medical center Down syndrome specialty clinic and the standard Centers for Disease Control and Prevention definitions, we calculated rates of obesity and overweight by age group and examined possible associations with common comorbidities including cardiac disease, thyroid disease, sleep apnea, autism, and visual and hearing impairment. We also examined mean body mass index (BMI) percentile and change in BMI percentile by age. Results. Data were obtained from 823 visits from 412 unique patients ranging in age from 2 years to 23 years of age. A total of 1.2% were underweight, 55.2% were normal weight, 23% were overweight, and 20.6% were obese. BMI percentile increased with female gender, age, and height percentile for age. Sleep apnea was associated with higher BMI percentile, while autism was associated with lower BMI percentile. Conclusions. Children with Down syndrome have higher rates of obesity than the general population, with especially high risk for girls. Much of the increase in obesity occurs between ages 2 and 6 years. Further research needs to target interventions for prevention in this vulnerable population, particularly in young girls.

Detecting Congenital Central Hypothyroidism by Newborn Screening: Difficulty in Distinguishing from Congenital Thyroxine-Binding Globulin Deficiency.

BACKGROUND/AIMS: Congenital central hypothyroidism (CH-C) can be detected on newborn screening (NBS) by programs using thyroxine (T4)-reflex thyroid-stimulating hormone (TSH) test approach. CH-C must be distinguished from T4-binding globulin (TBG) deficiency. We sought to determine whether thyroid function tests reliably separate CH-C from TBG deficiency. METHODS: We analyzed NBS and serum free and total T4, T3 resin uptake (T3RU) or TBG, and TSH for infants in the Northwest Regional NBS Program (NWRSP) between the years 2008 and 2015 with either CH-C or TBG deficiency. RESULTS: We discovered a significant overlap in T3RU and TBG levels amongst 21 cases of CH-C and 250 cases of TBG deficiency. Mean serum TBG levels were lower in CH-C cases (20.3 µg/mL, range 14.2-33.3) than what is reported in healthy infants (28.6 µg/mL, range 19.1-44.6). Serum free T4 was lower in CH-C cases than TBG deficiency but did not always differentiate between the two conditions. CONCLUSION: CH-C benefits from detection on NBS but must be distinguished from TBG deficiency. The diagnosis of CH-C rests solely on subnormal serum free T4, but is supported by the demonstration of other pituitary hormone deficiencies. As an overlap exists, serum TBG (or T3RU) levels do not play a role in the diagnosis of CH-C.

Characterization of Thyroid Abnormalities in a Large Cohort of Children with Down Syndrome
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BACKGROUND/AIMS: Thyroid disease is a common comorbidity in individuals with Down syndrome (DS), but historical studies have multiple limitations. We assessed thyroid abnormalities in a large cohort of children with DS. METHODS: Retrospective records review from a single institution. Calculated prevalence of common thyroid abnormalities and associations with common comorbidities. RESULTS: Among 508 patients, 120 (24%) had a thyroid-related diagnosis, the majority having elevated thyrotropin treated with levothyroxine. A Kaplan-Meier estimate projects that 50% have thyroid disorder by adulthood, with 20% of hypothyroidism diagnosed before the age of 6 months. When tested, approximately 50% had positive antithyroid antibodies, though this rate was 100% in overt hypothyroidism. There was no association between congenital or acquired hypothyroidism and common comorbidities. CONCLUSION: Thyroid disease in DS is more common and occurs earlier than in the general population, and is often transient. Thyroid disease is unrelated to gender, obesity, or other comorbidities. Apart from overt hypothyroidism, much of hypothyroidism in DS appears unrelated to autoimmunity; we recommend checking of antithyroid antibodies only in select cases. An additional screen for thyroid disease between the newborn screen and the 6-month well-child visit will detect early cases of hypothyroidism who passed their newborn screen.
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Biological features of placental programming.

The placenta is a key organ in programming the fetus for later disease. This review outlines nine of many structural and physiological features of the placenta which are associated with adult onset chronic disease. 1) Placental efficiency relates the placental mass to the fetal mass. Ratios at the extremes are related to cardiovascular disease risk later in life. 2) Placental shape predicts a large number of disease outcomes in adults but the regulators of placental shape are not known. 3) Non-human primate studies suggest that at about mid-gestation, the placenta becomes less plastic and less able to compensate for pathological stresses. 4) Recent studies suggest that lipids have an important role in regulating placental metabolism and thus the future health of offspring. 5) Placental inflammation affects nutrient transport to the fetus and programs for later disease. 6) Placental insufficiency leads to inadequate fetal growth and elevated risks for later life disease. 7) Maternal height, fat and muscle mass are important in combination with placental size and shape in predicting adult disease. 8) The placenta makes a host of hormones that influence fetal growth and are related to offspring disease. Unfortunately, our knowledge of placental growth and function lags far behind that of other organs. An investment in understanding placental growth and function will yield enormous benefits to human health because it is a key player in the origins of the most expensive and deadly chronic diseases that humans face.

Neonatal McCune-Albright syndrome with survival beyond two years.

McCune-Albright syndrome (MAS) is a rare disease resulting from a somatic, mosaic mutation of GNAS1 encoding the Gs α subunit of the G-protein coupled membrane receptor responsible for multiple hormonal signaling cascades. We present a patient with neonatal MAS who initially presented with neonatal diabetes and concern for congenital cardiac disease, and subsequently was found to have significant ACTH-independent neonatal Cushing syndrome. Her course included multi-system organ involvement, although she initially did not have obvious findings consistent with the MAS classic triad of café-au-lait macules, fibrous dysplasia, or peripheral precocious puberty. After medical and surgical treatment, she remains the only reported survivor of neonatal MAS. This clinical report alerts clinicians to the possibility of this disease in neonates with non-classical endocrine and non-endocrine manifestations of MAS, and demonstrates that this very early presentation is potentially survivable. © 2016 Wiley Periodicals, Inc.

The neurologic findings in Taybi-Linder syndrome (MOPD I/III): case report and review of the literature.

Taybi-Linder syndrome, also known as microcephalic osteodysplastic primordial dwarfism types I and III, is a rare disorder with presumed autosomal recessive inheritance. It is characterized by intrauterine growth retardation, distinctive bone dysplasia, and central nervous system malformations. We present two siblings with Taybi-Linder syndrome, with an emphasis on the neurological profile in this disease, which includes brain malformations, intractable epilepsy, sensory deficits, profound cognitive deficits, and neuroendocrine dysfunction. We also present distinctive correlative neuroimaging (MRI) and electroencephalographic (EEG) findings. Increased knowledge of the neurological profile of Taybi-Linder syndrome may be helpful for clinicians and genetic counselors managing these patients.