Invited Mini Review Metabolic Bone Disease of Prematurity: Overview and Practice Recommendations

Metabolic bone disease of prematurity (MBDP) is defined by undermineralization of the preterm infant skeleton arising from inadequate prenatal and postnatal calcium (Ca) and phosphate (PO4) accretion. Severe MBDP can be associated with rickets and fractures. Despite advances in neonatal nutrition, MBDP remains prevalent in premature infants due to inadequate mineral accretion ex-utero. There also remain significant knowledge gaps regarding best practices for monitoring and treatment of MBDP among neonatologists and pediatric endocrinologists. Preventing and treating MBDP can prevent serious consequences including rickets or pathologic fractures. Postnatal monitoring to facilitate early recognition of MBDP is best done by first-tier laboratory screening by measuring serum calcium, phosphorus, and alkaline phosphatase to identify infants at risk. If these labs are abnormal, further studies including assessing parathyroid hormone and/or tubular resorption of phosphate can help differentiate between Ca and PO4 deficiency as primary etiologies to guide appropriate treatment with mineral supplements. Additional research into optimal mineral supplementation for the prevention and treatment of MBDP is needed to improve long-term bone health outcomes and provide a fuller evidence base for future treatment guidelines.

Global Health Disparities in Childhood Rickets

Nutritional rickets is a global health problem reflecting both historical and contemporary health disparities arising from racial, ethnic, environmental, and geopolitical circumstances. It primarily affects marginalized populations and can contribute to long-term morbidity. Deficits in bone health in childhood may also contribute to osteomalacia/osteoporosis. Solutions require a global public health approach.

Transition of young adults with metabolic bone diseases to adult care

As more accurate diagnostic tools and targeted therapies become increasingly available for pediatric metabolic bone diseases, affected children have a better prognosis and significantly longer lifespan. With this potential for fulfilling lives as adults comes the need for dedicated transition and intentional care of these patients as adults. Much work has gone into improving the transitions of medically fragile children into adulthood, encompassing endocrinologic conditions like type 1 diabetes mellitus and congenital adrenal hyperplasia. However, there are gaps in the literature regarding similar guidance concerning metabolic bone conditions. This article intends to provide a brief review of research and guidelines for transitions of care more generally, followed by a more detailed treatment of bone disorders specifically. Considerations for such transitions include final adult height, fertility, fetal risk, heritability, and access to appropriately identified specialists. A nutrient-dense diet, optimal mobility, and adequate vitamin D stores are protective factors for these conditions. Primary bone disorders include hypophosphatasia, X-linked hypophosphatemic rickets, and osteogenesis imperfecta. Metabolic bone disease can also develop secondarily as a sequela of such diverse exposures as hypogonadism, a history of eating disorder, and cancer treatment. This article synthesizes research by experts of these specific disorders to describe what is known in this field of transition medicine for metabolic bone diseases as well as unanswered questions. The long-term objective is to develop and implement strategies for successful transitions for all patients affected by these various conditions.

OR18-3 Case Series of 16 Patients With 17β-Hydroxysteroid Dehydrogenase Type 3 Deficiency at Five Children's Hospitals in the United States

Objectives

The 17β-hydroxysteroid dehydrogenase type 3 (17βHSD3) enzyme, expressed in the testes, converts androstenedione to testosterone. Deficiency of 17βHSD3 causes a 46,XY difference of sex development (DSD). Until recently, just 12 cases of 17βHSD3 deficiency had been reported in the literature in the United States. We report a series of 16 patients diagnosed at five children's hospitals in the United States.

Methods

We performed a multi-center chart review of patients with 17βHSD3 deficiency diagnosed based on hormone values and/or sequencing and deletion/duplication analysis of the HSD17B3 gene.

Results

Sixteen patients were identified, ranging in age at diagnosis from birth to 22.3 years (average age 9.5 years). One patient, assigned female at birth, was diagnosed due to a positive family history of the condition. Three patients underwent testing due to discordance between the sex predicted by prenatal cell-free DNA testing and the external genital appearance on prenatal ultrasound or at birth (two were assigned female, one was assigned male). An additional four patients had non-binary (atypical) appearing external genitalia at birth (two assigned female, two assigned male). Two children assigned female at birth were diagnosed after undescended testes were identified during hernia repair in early childhood. Six patients who were assigned female at birth came to medical attention peri-pubertally due to signs of excess/undesired androgen effects and/or primary amenorrhea. Data on gender identity is limited by the current age of many of the patients, but as of most recent follow-up, one patient assigned male and one assigned female are reported to be exploring their gender identities.

Four patients had a prior diagnosis of complete or partial androgen insensitivity syndrome and 8 had a prior diagnosis of 46,XY DSD of unknown etiology. Eleven patients had genetic testing confirming pathogenic or likely pathogenic variants in the HSD17B3 gene (two identified on whole exome, one on a DSD-specific multi-gene panel, and the remaining 8 on single gene testing). Of the patients without genetically confirmed 17βHSD3 deficiency, one had a clinical diagnosis due to a genetically-confirmed diagnosis in a sibling. The remaining four declined or have not completed genetic testing, but had hormonal testing consistent with the diagnosis.

Conclusions

17βHSD3 deficiency is likely much more common in the US than previously appreciated, and can present at any age with a range of physical findings. Accurate diagnosis is important, as the broad category of 46,XY DSD encompasses a wide spectrum of gonadal malignancy risk, potential for pubertal hormone function and fertility, and gender identity outcomes. We suggest evaluating for this potential diagnosis with genetic and/or hormonal testing in cases of 46,XY DSD with absent uterus.

Presentation: Monday, June 13, 2022 11:30 a.m. - 11:45 a.m.

Treatment Practices and Confidence in the Management of Pediatric Metabolic Bone Disorders

INTRODUCTION

Pediatric metabolic bone and mineral disorders encompass a wide variety of disorders that can be challenging to diagnose and treat because of inadequate physician training about optimal management.

METHODS

As practice variation and confidence levels may impact clinical outcome, we sought to assess physician confidence in managing pediatric metabolic bone and mineral disorders and the spectrum of treatment practices among members of the Pediatric Endocrine Society (PES) and the Canadian Pediatric Endocrine Group (CPEG). Questionnaires were distributed via e-mail to all members of the PES and CPEG and 244 were completed. Responses were summarized using descriptive statistics, and proportions were compared using χ2 or Fisher's exact tests, as appropriate.

RESULTS

Variations were observed among the respondents' confidence in the management of bone disorders and in the criteria used to initiate/discontinue intravenous bisphosphonates or prescribe burosumab therapy. Respondents felt confident with the management of 4 out of 20 pediatric bone conditions (confidence was defined as >90% of respondents reporting feeling "somewhat confident" or "very confident"). Physicians working in a bone clinic were more confident in prescribing burosumab for the treatment of X-linked hypophosphatemic rickets compared to those not working in a bone clinic (65% vs. 47%, p = 0.03). Most respondents (52%) reported having received inadequate training in pediatric metabolic bone and mineral disorders.

DISCUSSION/CONCLUSION

Dedicated training, knowledge acquisition, and education resources are needed to increase confidence and standardize the use of bone-targeted therapies.

Cushing syndrome as a failed cardiac screen in a patient with McCune–Albright syndrome: a case report

Background

McCune–Albright syndrome is a complex disorder encompassing multiple endocrinopathies. These manifestations are secondary to a mutation in the stimulatory G-protein alpha subunit. Cushing syndrome is due to autonomous secretory function of the adrenal gland and is present in 7.1% of patients with McCune–Albright syndrome. Cardiac newborn screenings assist in the identification of critical congenital heart disease. These screenings have become part of routine postnatal care nationwide.

Case report

A 6-week-old Caucasian male presented to a cardiologist at the University of Tennessee Health Science Center with left ventricular hypertrophy and poor feeding after a failed cardiac newborn screen. He had been previously seen at 2 weeks by a cardiologist on follow-up for abnormal critical congenital heart disease screening. Electrocardiogram and echocardiographic studies identified hypertrophic cardiomyopathy. Other examination findings revealed multiple characteristic café-au-lait lesions along with hypotonia and rounded facies. Given his cardiac disease, he was admitted to the hospital, where an evaluation was done for Cushing syndrome, showing elevated cortisol by immunoassay of 38 μg/dL (1.7–14.0 μg/dL, Vitros 5600) after a dexamethasone suppression test and urinary cortisol elevated to 35 μg/dL/24 hours (reference range 3–9 μg/dL/24 hours) (Esoterix; Calabasas, CA). He was started on metyrapone therapy to block synthesis of cortisol. His cortisol improved and was suppressed less than 2 μg/dL. His hypertension and clinical features of Cushing syndrome improved.

Conclusions

This case demonstrates a unique presentation of Cushing syndrome in a young infant. This is the first case to our knowledge showing significant left ventricular hypertrophy resulting from Cushing syndrome identified following a failure on a critical congenital heart disease screen. It highlights the importance of considering of McCune–Albright syndrome in patients with Cushing syndrome, especially if other clinical features are present. Medical therapy can be used to treat Cushing syndrome and can result in improvement in the cardiovascular pathology.

How Peer Conflict Profiles and Socio-Demographic Factors Influence Type 1 Diabetes Adaptation

OBJECTIVE

This study aimed to (a) validate the factor structure for a measure of peer conflict in youth with type 1 diabetes (T1D); (b) determine empirical patterns of peer conflict in terms of context (friend vs. nonfriend) and content (diabetes-specific vs. general) within a broader context of socio-demographic factors; and (c) examine how these patterns and socio-demographic factors relate to adolescents' T1D adherence, quality of life, and glycemic control (HbA1c).

METHODS

Youth with T1D (N = 178), ages 12-18, reported demographic variables, illness duration, adherence, quality of life, and peer conflict. HbA1c was extracted from medical records. Confirmatory factor analysis validated a factor structure for the Diabetes Peer Conflict Scale (DPCS) and latent profile analysis (LPA) determined profiles of peer conflict.

RESULTS

A four-factor structure emerged for the DPCS: general friend conflict, general nonfriend conflict, T1D friend conflict, and T1D nonfriend conflict. Using these factors as indicators in LPA, four profiles were confirmed: (a) Low Overall Conflict (LOC) and (b) Moderate Overall Conflict (MOC), (c) a Nonfriend Conflict (NFC), and (d) a Friend Conflict (FC) profile. Differences were not identified between diabetes specific versus general conflict. Socio-demographic variables did not predict class membership. The LOC profile reported the highest quality of life and best glycemic control, whereas the FC profile reported the lowest adherence behaviors. Conclusions: Peer conflict uniquely contributes to diabetes adaptation above and beyond socio-demographic and illness factors.

Newborn Screening Protocols and Positive Predictive Value for Congenital Adrenal Hyperplasia Vary across the United States

Newborn screening for congenital adrenal hyperplasia (CAH) caused by 21-hydroxylase deficiency is mandated throughout the US. Filter paper blood specimens are assayed for 17-hydroxyprogesterone (17OHP). Prematurity, low birth weight, or critical illness cause falsely elevated results. The purpose of this report is to highlight differences in protocols among US state laboratories. We circulated a survey to state laboratory directors requesting qualitative and quantitative information about individual screening programs. Qualitative and quantitative information provided by 17 state programs were available for analysis. Disease prevalence ranged from 1:9941 to 1:28,661 live births. Four state laboratories mandated a second screen regardless of the initial screening results; most others did so for infants in intensive care units. All but one program utilized birthweight cut-points, but cutoffs varied widely: 17OHP values of 25 to 75 ng/mL for birthweights >2250-2500 g. The positive predictive values for normal birthweight infants varied from 0.7% to 50%, with the highest predictive values based in two of the states with a mandatory second screen. Data were unavailable for negative predictive values. These data imply differences in sensitivity and specificity in CAH screening in the US. Standardization of newborn screening protocols could improve the positive predictive value.

Low prevalence of organic pathology in a predominantly black population with premature adrenarche: need to stratify definitions and screening protocols

Background

Premature adrenarche has been described as clinical and biochemical hyperandrogenism before the age of 8 years in girls and 9 years in boys and absence of signs of true puberty. Adrenal pathology such as adrenal tumors or non-classical congenital adrenal hyperplasia (NCCAH) and exogenous androgen exposure need to be excluded prior to diagnosing (idiopathic) premature adrenarche. Premature adrenarche is more common among black girls compared to white girls and other racial groups. Adrenal pathology such as NCCAH is less common as a cause for premature adrenarche compared with idiopathic premature adrenarche. The evaluation guidelines for premature adrenarche however are not individualized based on racial/ethnic differences. Few studies have been done to evaluate a largely black population with premature adrenarche to assess the incidence of adrenal pathology.

Methods

This cross-sectional retrospective study evaluated characteristics of prepubertal patients seen in an endocrine clinic for premature adrenarche.

Results

Two hundred and seventy three subjects had signs of early adrenarche. Three subjects were found to have CAH (2 with NCCAH and 1 with late diagnosis classical CAH). None were black. Exogenous androgen exposure was etiology in 4 additional subjects. These 7 patients were excluded from further analysis. The remaining subjects had idiopathic PA (n = 266); 76.7% were females. The mean age at initial visit was 6.42 +/− 1.97 years (with no racial difference) although black subjects were reported symptom onset at a significantly younger age compared to non-Hispanic white patients.

Conclusions

Our study showed organic pathology was very uncommon in a predominantly black population with premature adrenarche. Patient factors that influence the probability of an underlying organic pathology including race/ ethnicity should be considered to individualize evaluation.

MON-518 Osteoporosis in a Young Adult with Trisomy 13

Background: Trisomy 13 is associated with multiple congenital anomalies, including cleft lip/palate, microcephaly, polydactyly, rocker bottom feet, iris coloboma, holoprosencephaly, seizures, heart defects, kidney malformations, respiratory distress, and feeding difficulties (1). It affects approximately 1 in 12,000 live births, and median survival time is 7-10 days, with a 5-year survival of 9.7%, although a few reports exist of survival into the second decade (2). Clinical Case: A 20-year-old male with trisomy 13 presented to endocrinology clinic for evaluation of osteoporosis. He was diagnosed with trisomy 13 by prenatal amniocentesis, confirmed by karyotype after birth. He has a history of Dandy-Walker malformation, holoprosencephaly, severe developmental delay, ventricular septal defect, dextrocardia, partial situs inversus, omphalocele, cleft lip and palate, pancreatitis, malposition of the duodenum, neurogenic bladder, gastrostomy tube dependence, left iris coloboma, scoliosis, and wheelchair dependence since age 12. Parents reported that he had no history of thyroid or adrenal dysfunction. He briefly received growth hormone injections, but these were stopped by the parents. On physical exam, he had buried micropenis and one palpable testis, 3-4 mL. DXA scan showed severe reduced bone mineral density of the lumbar spine (L1-L4) with Z score of -9.6. Radiography of the spine revealed compression deformities of thoracic vertebrae 3, 4, and 11. Serum calcium was 9.7 mg/dL (8.4 - 10.2 mg/dL), and phosphorus level was 4.8 mg/dL (3.1 - 5.6 mg/dL). Vitamin D level was 48.2 ng/ml (30.0 - 70.0). The patient had a low-trauma fracture of the left foot in 2011. MRI of the brain showed a grossly normal appearing pituitary gland. Laboratory studies were obtained, including TSH 2.270 mcIU/mL (0.358 - 3.740 mcIU/mL); free T4 1.44 ng/dL (0.80 - 2.00 ng/dL); LH 0.104 IU/L (1.5 - 9 IU/L); FSH 0.974 IU/mL (2.0 - 9.2 IU/mL); total testosterone <2.5 ng/dL (264 - 916 ng/dL); free testosterone <0.2 pg/mL (52-280 pg/mL); IGF-1 64 ng/mL (281-510 ng/mL); IGF-BP3 antibody 3.62 mg/L (2.72 - 6.36 mg/L). The patient had multiple risk factors for osteoporosis, including hypogonadism, growth hormone deficiency, and non-ambulatory status. He was prescribed testosterone cypionate. Follow up was planned for 4 months after the initial visit. Conclusion: Our case reporting osteoporosis in Trisomy 13 is unique, with no other case reports describing this syndrome found in the literature. This is likely due to his unusual prolonged survival. References: (1) Bruns DA, Campbell E. 2014. Nine children over the age of one year with full trisomy13: A case series describing medical conditions. Am J Med Genet Part A 164A:2987-2995. (2) Meyer RE et al. Survival of children with trisomy 13 and trisomy 18: A multi-state population-based study. Am J Med Genet A. 2016 Apr;170A(4):825-37.

SAT-LB084 Persistent Cushing Disease in a Prepubertal Pediatric Patient after Gross Total Resection: What to Expect

Cushing disease (CD), which is ACTH-dependent hypercortisolism is an exceedingly rare condition in pediatrics. The exact annual incidence is unknown but estimated to be approximately 0.7-2.4 cases per million people, with approximately 10% occurring in children, making the incidence in pediatrics <0.5 per million.(Lodish, et al. 2018; Sharma, et al. 2015) Of the pediatric cases, few are prepubertal. Of the pituitary tumors, microadenomas are most common. Pituitary macroadenomas accounts for 5-10% of all cases Cushing disease. The first line therapy is surgical resection of the adenoma. Remission rates are better with microadenomas (~75%) compared with macroadenomas (~43%).(Nieman et al. 2015) If a surgical resection is not curative, defined by the persistent elevation of morning serum cortisol > 5 μg/dl, then second-line therapies are required. We describe a 9-year-old African American female who initially presented with symptoms of significant weight gain, lower extremity edema and hypertension. Initial random (late-morning) serum cortisol level was 38.3 μg/dl and ACTH 99 pg/ml. Ultrasound of adrenal glands did not show any distinct masses. MRI brain showed 1.9 cm macroadenoma in the sella. She underwent transsphenoidal resection. Histology confirmed an ACTH-secreting tumor without atypical features: Ki67 <3%, P53 negative. Postoperatively, serum cortisol levels remained elevated to as high as 23.1 μg/dl. In the subsequent weeks following surgery, cortisol levels at different times of day demonstrated loss of normal diurnal rhythm. She also developed symptoms of headaches, anorexia and vomiting. Interestingly, repeat MRI brain was performed but did not show any residual tumor despite persistent biochemical CD. Persistent CD is defined as a sustained elevation in post-surgical cortisol levels. It may be secondary to residual tumor hidden within the gland, or invasion into the cavernous sinus or other neighboring spaces.(Nieman et al. 2015) The family should be included in the medical decision making regarding second line therapies given the long-term health related quality of life issues surrounding patients with CD. Second line therapies include repeat transsphenoidal surgery, radiotherapy, medical therapy, or bilateral adrenalectomy.(Nieman et al. 2015) Multiple comorbidities need to be addressed in the treatment of CD, on the one hand with persistent disease, hypertension, hyperglycemia, obesity and on the other hand with curative resection, possible panhypopituitarism and/or adrenal insufficiency. Patients may also suffer from “glucocorticoid withdrawal syndrome” secondary to relative deficiency of cortisol with symptoms of anorexia, nausea and fatigue and may require psychosocial support. (Nieman et al. 2015) Regardless of if the initial therapy was curative or not, patients with CD require long-term monitoring of secondary comorbidity outcomes. Unless otherwise noted, all abstracts presented at ENDO are embargoed until the date and time of presentation. For oral presentations, the abstracts are embargoed until the session begins. Abstracts presented at a news conference are embargoed until the date and time of the news conference. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to or during ENDO.

Intracranial pathologies associated with central diabetes insipidus in infants

Background Idiopathic central diabetes insipidus (CDI) has been associated with intracranial pathologies that do not involve the structural pituitary gland or hypothalamus. The objective was to study the association between non-structural hypothalamic/pituitary intracranial pathologies (NSHPIP) with CDI and to review etiologies that may be contributory to the development of CDI. Methods A retrospective query of our intra-institutional database from 2006 to 2015. Children admitted diagnosed with diabetes insipidus (DI) (ICD-9 253.5) between the ages of 0-1 year were included. Patient charts were reviewed to include those who have a documented diagnosis of CDI, hypernatremia (>145 mmol/L), high serum osmolality (>300 mOsm/kg), low urine osmolality (<300 mOsm/kg), and brain imaging reports. Diagnoses of nephrogenic DI were excluded. Results Twenty-three infant patients were diagnosed with CDI. Eleven subjects (48%) had NSHPIP. Of those, 18% had cerebral infarction, 27% had intracranial injury and hemorrhage due to traumatic brain injury, 18% had isolated intraventricular hemorrhage, and 27% had meningitis. Hospital prevalence for NSHPIP, age 0-1 year, ranged from 0.05% to 0.3%. Conclusions Rates of NSHPIP in those with CDI are higher than expected hospital rates (p<0.001), suggesting a possible association between CDI and NSHPIP.

Delayed Puberty

Delayed puberty is defined as the absence of physical signs of puberty 2 to 2.5 standard deviations above the mean age and affects approximately 2% of adolescents. Causes of delayed puberty are broadly divided into two categories: hypergonadotropic hypogonadism and hypogonadotropic hypogonadism. One exception to this classification system is constitutional delay of growth and puberty, the most common cause of delayed puberty. For the general pediatrician, knowledge of the different causes and initial steps to evaluation is crucial when a patient with delayed puberty presents. [Pediatr Ann. 2018;47(1):e16-e22.].

A novel CASR mutation associated with neonatal severe hyperparathyroidism transmitted as an autosomal recessive disorder

BACKGROUND

Neonatal severe primary hyperparathyroidism (NSHPT, MIM 239200) is most often an isolated disorder that is due to biallelic inactivating mutations in the CASR, the gene encoding the calcium sensing receptor; NSHPT is inherited from parents with familial hypocalciuric hypercalcemia, each of whom has one mutated CASR allele.

OBJECTIVES

To report clinical and genetic findings in a brother and sister with NSHPT due to a novel mutation in the CASR transmitted as an autosomal recessive trait and to examine the functional effect of the mutation.

SUBJECTS AND METHODS

A brother and sister with marked hypercalcemia due to NSHPT were identified; the boy also had craniosynostosis requiring surgical repair. The genotyping of the CASR in both children and their parents who were eucalcemic and normophosphatemic was undertaken. In order to examine the significance of the variant CASR identified, the CASR variant was expressed in vitro and examined by three computer computational programs [PolyPhen2, MutationTaster, Sorting Intolerant From Tolerant (SIFT)] designed to evaluate the effect of a nucleotide variant on the structure and likely functional consequence upon the protein product.

RESULTS

A sequence variant in the CASR was identified [G>T point mutation at nucleotide c.2303 in exon 7 (c.2303G>T) resulting in the replacement of glycine by valine at codon 768 (p.Gly768Val)]. Two copies of this CASR variant were present in the genome of the siblings while a single copy of the CASR variant was present in both of the clinically and biochemically normal parents, a pattern of transmission consistent with autosomal recessive inheritance of NSHPT in this family. When expressed in HEK293 cells in vitro, the novel Gly768Val variant did not interfere with protein generation or migration to the cell membrane in vitro. The analysis of the functional effect of the Gly768Val CASR variant by the PolyPhen2, MutationTaster, and Sorting Intolerant From Tolerant computer programs revealed that this mutation was very likely to be deleterious.

CONCLUSION

The NSHPT associated with biallelic Gly768Val mutations of the CASR in two siblings with severe hypercalcemia and hyperparathyroidism and their clinically and biochemically normal heterozygous parents was transmitted as an autosomal recessive disorder in this family.

Problems with the new born screen for galactosaemia

The new born screen should identify asymptomatic children with a devastating disorder before the damage has occurred. One family had two children born with classical galactosaemia. The first child, subject to a flaw in the newborn screening program, was not detected, went into rapid liver failure and ultimately had a liver transplant. The second child was following the same devastating course when identified by the new born screen with reduced galactose-1-phosphate uridyl transferase activity in a blood spot. The rapid response of the second child to removal of lactose and galactose from the diet resulted in significant clinical improvement. If the screening test for an inborn genetic defect involves the measurement of enzyme activity in red blood cells, be sure the patient has only native red blood cells. The events leading to the failure of the galactosaemia screening test are reviewed, so physicians will be aware and avoid this problem.