Pancreas-related persisting sequelae in ALL survivors with a history of asparaginase-associated pancreatitis: A part of the ALL-STAR study.

OBJECTIVES: Asparaginase-associated pancreatitis (AAP) occurs in up to 18% of patients treated for acute lymphoblastic leukemia (ALL); however, long-term sequelae are largely unexplored. We aimed to explore pancreatic sequelae among ALL survivors with and without AAP. METHODS: We investigated pancreatic sequelae in a national cohort of ALL survivors, aged 1-45 years at ALL diagnosis treated according to the NOPHO-ALL2008 protocol and included sex- and age-matched community controls. RESULTS: We included 368 survivors (median follow-up 6.9 years), including 47 survivors with AAP and 369 controls. The p-lipase and p-pancreas-type amylase levels were lower in AAP survivors compared with both non-AAP survivors (Medians: 23 U/L [IQR 14-32] and 18 U/L [IQR 10-25] versus 29 [IQR 24-35] and 22 [17-28], p < .001 and p = .002) and community controls (28 U/L [IQR 22-33] and 21 U/L [IQR 17-26], both p < .006). Fecal-elastase was more frequently reduced in AAP survivors compared with non-AAP survivors (7/31 vs. 4/144, p = .001). Persisting pancreatic sequelae were found in 15/47 of AAP survivors and 20/323 of non-AAP survivors (p < .001), including diabetes mellitus in 2/39 of AAP survivors and 2/273 of non-AAP survivors. CONCLUSIONS: ALL survivors with AAP are at increased risk of persisting pancreatic dysfunction and require special attention during follow-up.

Hormonal control during infancy and testicular adrenal rest tumor development in males with congenital adrenal hyperplasia: a retrospective multicenter cohort study.

IMPORTANCE: Testicular adrenal rest tumors (TARTs), often found in male patients with congenital adrenal hyperplasia (CAH), are benign lesions causing testicular damage and infertility. We hypothesize that chronically elevated adrenocorticotropic hormone exposure during early life may promote TART development. OBJECTIVE: This study aimed to examine the association between commencing adequate glucocorticoid treatment early after birth and TART development. DESIGN AND PARTICIPANTS: This retrospective multicenter (n = 22) open cohort study collected longitudinal clinical and biochemical data of the first 4 years of life using the I-CAH registry and included 188 male patients (median age 13 years; interquartile range: 10-17) with 21-hydroxylase deficiency (n = 181) or 11-hydroxylase deficiency (n = 7). All patients underwent at least 1 testicular ultrasound. RESULTS: TART was detected in 72 (38%) of the patients. Prevalence varied between centers. When adjusted for CAH phenotype, a delayed CAH diagnosis of >1 year, compared with a diagnosis within 1 month of life, was associated with a 2.6 times higher risk of TART diagnosis. TART onset was not predicted by biochemical disease control or bone age advancement in the first 4 years of life, but increased height standard deviation scores at the end of the 4-year study period were associated with a 27% higher risk of TART diagnosis. CONCLUSIONS AND RELEVANCE: A delayed CAH diagnosis of >1 year vs CAH diagnosis within 1 month after birth was associated with a higher risk of TART development, which may be attributed to poor disease control in early life.

Diagnosis and Incidence of Congenital Combined Pituitary Hormone Deficiency in Denmark-A National Observational Study.

CONTEXT: Congenital combined pituitary hormone deficiency (cCPHD) is the loss of ≥2 pituitary hormones caused by congenital factors. OBJECTIVE: We aimed to estimate the national incidence of cCPHD diagnosed before age 18 years and in subgroups. METHODS: Patients with cCPHD were identified in the Danish National Patient Registry and Danish hospital registries in the period 1996-2020. Hospital files were reviewed and incidences calculated using background population data. Incidence was the main outcome measure. RESULTS: We identified 128 patients with cCPHD; 88 (68.8%) were males. The median (range) age at diagnosis was 6.2 (0.01-19.0) years. The median (25th;75th percentile) number of hormone deficiencies at diagnosis was 3 (3; 4) at <1 year vs 2 (2; 2) at 1-17 years, P < .0001. Abnormal pituitary magnetic resonance imaging findings were seen in 70.3% (83/118). For those born in Denmark aged <18 years at diagnosis (n = 116/128) the estimated national incidence (95% CI) of cCPHD was 10.34 (7.79-13.72) per 100 000 births, with an annual incidence rate of 5.74 (4.33-7.62) per million. In subgroup analysis (diagnosis <1 vs 1-17 years), the incidence was highest in the 1-17 years subgroup, 7.97 (5.77-11.00) vs 1.98 (1.39-2.84) per 100 000 births, whereas the annual incidence rate was highest at <1 year, 19.8 (13.9-28.4) vs 4.69 (3.39-6.47) per million births. CONCLUSION: cCPHD had the highest incidence rate and the most hormone deficiencies in those diagnosed at <1 year. The incidence was highest in the 1-17 years age group, underscoring the need for multiple pituitary hormone investigations throughout childhood and adolescence in children with only 1 hormone deficiency.

Growth hormone deficiency in adult survivors of childhood brain tumors treated with radiation.

Objective: Growth hormone deficiency (GHD) is the most common endocrine late effect in irradiated survivors of childhood brain tumors. This study aimed to determine the prevalence of GHD in adults treated with proton or photon irradiation for a brain tumor in childhood and to detect undiagnosed GHD. Design: This study is a cross-sectional study. Methods: We investigated GHD in 5-year survivors from two health regions in Denmark treated for childhood brain tumors with cranial or craniospinal irradiation in the period 1997-2015. Medical charts were reviewed for endocrinological and other health data. Survivors without a growth hormone (GH) test at final height were invited to a GH stimulation test. Results: Totally 41 (22 females) survivors with a median age of 21.7 years (range: 15.1-33.8 years) at follow-up and 14.8 years (range: 5.1-23.4 years) since diagnosis were included; 11 were treated with proton and 30 with photon irradiation; 18 of 21 survivors were previously found to have GHD; 16 of 20 survivors with no GH test at final height were tested, 8 (50 %) had GHD. In total, 26 of 41 patients (63%) had GHD. Insulin-like growth factor-1 (IGF-1) is associated poorly with the insulin tolerance test (ITT). Conclusion: This study identified a high prevalence of undiagnosed GHD in survivors with no GH test at final height. The results stress the importance of screening for GHD at final height in survivors of childhood brain tumors with prior exposure to cranial irradiation, irrespective of radiation modality and IGF-1. Significance statement: This cross-sectional study reports a prevalence of 63% of GHD in irradiated childhood brain tumor survivors. Furthermore, the study identified a considerable number of long-term survivors without a GH test at final height, of whom, 50% subsequently were shown to have undiagnosed GHD. Additionally, this study confirmed that a normal serum IGF-1 measurement cannot exclude the diagnosis of GHD in irradiated survivors. This illustrates the need for improvements in the diagnostic approach to GHD after reaching final height in childhood brain tumor survivors at risk of GHD. In summary, our study stresses the need for GHD testing in all adult survivors treated with cranial irradiation for a brain tumor in childhood irrespective of radiation modality.

Differences in retinopathy prevalence and associated risk factors across 11 countries in three continents: A cross-sectional study of 156,090 children and adolescents with type 1 diabetes.

OBJECTIVE: To examine the prevalence, time trends, and risk factors of diabetic retinopathy (DR) among youth with type 1 diabetes (T1D) from 11 countries (Australia, Austria, Denmark, England, Germany, Italy, Luxemburg, Netherlands, Slovenia, United States, and Wales). SUBJECTS AND METHODS: Data on individuals aged 10-21 years with T1D for >1 year during the period 2000-2020 were analyzed. We used a cross-sectional design using the most recent year of visit to investigate the time trend. For datasets with longitudinal data, we aggregated the variables per participant and observational year, using data of the most recent year to take the longest observation period into account. DR screening was performed through quality assured national screening programs. Multiple logistic regression models adjusted for the year of the eye examination, age, gender, minority status, and duration of T1D were used to evaluate clinical characteristics and the risk of DR. RESULTS: Data from 156,090 individuals (47.1% female, median age 15.7 years, median duration of diabetes 5.2 years) were included. Overall, the unadjusted prevalence of any DR was 5.8%, varying from 0.0% (0/276) to 16.2% between countries. The probability of DR increased with longer disease duration (aORper-1-year-increase  = 1.04, 95% CI: 1.03-1.04, p < 0.0001), and decreased over time (aORper-1-year-increase  = 0.99, 95% CI: 0.98-1.00, p = 0.0093). Evaluating possible modifiable risk factors in the exploratory analysis, the probability of DR increased with higher HbA1c (aORper-1-mmol/mol-increase-in-HbA1c  = 1.03, 95% CI: 1.03-1.03, p < 0.0001) and was higher among individuals with hypertension (aOR = 1.24, 95% CI: 1.11-1.38, p < 0.0001) and smokers (aOR = 1.30, 95% CI: 1.17-1.44, p < 0.0001). CONCLUSIONS: The prevalence of DR in this large cohort of youth with T1D varied among countries, increased with diabetes duration, decreased over time, and was associated with higher HbA1c, hypertension, and smoking.

Analysis of therapy monitoring in the International Congenital Adrenal Hyperplasia Registry.

OBJECTIVE: Congenital adrenal hyperplasia (CAH) requires exogenous steroid replacement. Treatment is commonly monitored by measuring 17-OH progesterone (17OHP) and androstenedione (D4). DESIGN: Retrospective cohort study using real-world data to evaluate 17OHP and D4 in relation to hydrocortisone (HC) dose in CAH patients treated in 14 countries. PATIENTS: Pseudonymized data from children with 21-hydroxylase deficiency (21OHD) recorded in the International CAH Registry. MEASUREMENTS: Assessments between January 2000 and October 2020 in patients prescribed HC were reviewed to summarise biomarkers 17OHP and D4 and HC dose. Longitudinal assessment of measures was carried out using linear mixed-effects models (LMEM). RESULTS: Cohort of 345 patients, 52.2% female, median age 4.3 years (interquartile range: 3.1-9.2) were taking a median 11.3 mg/m2 /day (8.6-14.4) of HC. Median 17OHP was 35.7 nmol/l (3.0-104.0). Median D4 under 12 years was 0 nmol/L (0-2.0) and above 12 years was 10.5 nmol/L (3.9-21.0). There were significant differences in biomarker values between centres (p < 0.05). Correlation between D4 and 17OHP was good in multiple regression with age (p < 0.001, R2 = 0.29). In longitudinal assessment, 17OHP levels did not change with age, whereas D4 levels increased with age (p < 0.001, R2 = 0.08). Neither biomarker varied directly with dose or weight (p > 0.05). Multivariate LMEM showed HC dose decreasing by 1.0 mg/m2 /day for every 1 point increase in weight standard deviation score. DISCUSSION: Registry data show large variability in 17OHP and D4 between centres. 17OHP correlates with D4 well when accounting for age. Prescribed HC dose per body surface area decreased with weight gain.

Overeating, binge eating, quality of life, emotional difficulties, and HbA1c in adolescents with type 1 diabetes: A Danish national survey.

AIMS: To determine 1) the prevalence of symptoms of overeating (OE), subclinical binge eating (SBE) and clinical binge eating (CBE), in adolescents with type 1 diabetes (T1D), and 2) their associations with quality of life (QoL), anxiety, depression, HbA1c, and body mass index standard deviation score (BMISDS). METHODS: In total 506 adolescents (age 12-17 years; mean 14.7 years; girls 49%) from the Danish Registry for Diabetes in Childhood and Adolescence (DanDiabKids) were included. Participants completed questionnaires on disordered eating, QoL, and emotional difficulties. A blood sample was sent for HbA1c determination. BMISDS was determined from the DanDiabKids data. RESULTS: Prevalence rates of OE, SBE, and CBE were 8.4%, 18% and 7.9% respectively. Youth with CBE symptoms scored lowest on generic and diabetes specific QoL, highest on anxiety and depression symptoms, and had a higher HbA1c. Youth with CBE had borderline increased BMISDS. CONCLUSIONS: In a Danish national survey of adolescents with T1D, approximately one-third of participants had overeating or binge eating symptoms, comparable with the numbers in a U.S T2D population. Increased binge eating symptoms associated with lower QoL, higher depression scores, higher anxiety scores, and poorer clinical outcomes. Binge eating symptoms were markers for poor mental and somatic health.

Surgical Practice in Girls with Congenital Adrenal Hyperplasia: An International Registry Study.

In this article international trends in surgical practice in girls with congenital adrenal hyperplasia (CAH) are evaluated. All cases that had been classified in the I-CAH/I-DSD registry as 46,XX CAH and who were born prior to 2017 were identified. Centers were approached to obtain information on surgical decision making. Of the 330 included participants, 208 (63.0%) presented within the first month of life, and 326 (98.8%) cases were assigned female. Genital surgery had been performed in 250 (75.8%). A total of 64.3, 89.2, and 96.8% of cases residing in Europe, South America and Asia, respectively, had at least one surgery. In a logistic regression model for the probability of surgery before the second birthday (early surgery) over time an increase of probability for early vaginal surgery could be identified, but not for clitoral surgery or both surgeries combined. Genitoplasty in girls with CAH remains controversial. This large international study provides a snapshot of current practice and reveals geographical and temporal differences. Fewer surgeries were reported for Europe, and there seems to be a significant trend towards aiming for vaginal surgery within the first 2 years of life.

Screening for retinopathy in children with type 1 diabetes in Denmark.

BACKGROUND/OBJECTIVE: Children with type 1 diabetes (T1D) are screened regularly for retinopathy with fundus photography to prevent visual impairment. According to Danish national guidelines, screening should take place at age 12, 15, and 18 years after minimum 3 years of diabetes. As glycemic control has improved, prevalence of retinopathy is expected to be decreased. The aim of this study is to investigate the prevalence, degree, and progression of retinopathy in children with T1D and to explore if screening at 12 years is currently indicated in Denmark. METHODS: Data on all Danish children with onset of T1D from 2003 to 2013 (n = 2943) were collected from the "DanDiabKids" registry. For children with registered screenings (n = 2382), prevalence of retinopathy at 12, 15, and 18 years was determined. In children with retinopathy, subsequent screenings were studied to reveal if retinopathy was persistent or temporary. RESULTS: Prevalence of retinopathy at 12, 15, and 18 years was 0.9%, 2.3%, and 3.1%, respectively. Minimal background retinopathy was seen in over 90% and 100% at 12 years. In available re-screenings, retinopathy resolved spontaneously in 87.5% of all cases and 100% of cases at 12 years. CONCLUSIONS: The prevalence of retinopathy in Danish children with T1D was low. At 12 years, prevalence was 0.9% and exclusively minimal background retinopathy with 100% remission in re-screenings. Thus, screening at this age does not seem to have significant clinical relevance. We propose more individualized screening selection before the age of 15.

The follicle-stimulating hormone (FSH) and luteinizing hormone (LH) response to a gonadotropin-releasing hormone analogue test in healthy prepubertal girls aged 10 months to 6 years.

OBJECTIVE: Premature thelarche and precocious puberty are frequently diagnosed in girls even below 6 years of age and may be difficult to differentiate in the early stages. A GnRH test is often included in the diagnostic work-up, although interpretation of the GnRH test in girls below 6 years of age is challenging, as no reference interval exists for this age group. The objective is to determine the normal FSH and LH response to a GnRH test in healthy prepubertal girls below 6 years of age. DESIGN AND METHODS: A standardized GnRH test, baseline reproductive hormones, clinical evaluation and bone age were determined in all participants. Forty-eight healthy normal-weight girls aged 3.5 ± 0.2 years (range: 0.8-5.9 years) were included. Serum concentrations of LH and FSH were measured before and 30 min after the gonadorelin injection. RESULTS: The 30-min LH responses (mean ± 2 s.d.) were 5.2 ± 4.0 and 2.9 ± 2.5 IU/L and the FSH responses were 23.3 ± 16.2 and 14.5 ± 10.3 IU/L in girls aged 0.8-3.0 years and 3.0-5.9 years respectively. This corresponds to upper cut-off limits for LH of 9.2 IU/L (<3 years) and 5.3 IU/L (3-6 years). The stimulated LH/FSH ratio was 0.23 ± 0.19 (range 0.06-0.43) and did not correlate with age. CONCLUSIONS: We found that LH increases up to 9.2 IU/L during GnRH test in healthy normal-weight girls below 3 years of age and that the stimulated LH/FSH ratio did not exceed 0.43. Our findings have important implications for appropriate diagnosis of central precocious puberty in girls below 6 years of age.

Effect of first line cancer treatment on the ovarian reserve and follicular density in girls under the age of 18 years.

OBJECTIVE: To study the impact of first-line antineoplastic treatment on ovarian reserve in young girls returning for ovarian tissue cryopreservation (OTC) in connection with a relapse. DESIGN: Retrospective case-control study. SETTING: University hospitals. PATIENT(S): Sixty-three girls under the age of 18 years who underwent OTC before (group 1: 31 patients) and after (group 2: 32 patients) their initial cancer treatment. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Follicular densities (follicles/mm3) measured from an ovarian cortical biopsy before OTC. The ovarian volume (mL) of entire ovaries excised for OTC was also monitored. RESULT(S): There was no statistically significant difference in the mean age or follicular density between groups 1 and 2 (334 ± 476/mm3 vs. 327 ± 756/mm3). In contrast, the ovarian volume and total number of ovarian cortex chips cryopreserved were statistically significantly lower in patients who received gonadotoxic treatment before OTC (mean ± standard deviation [SD]: ovarian volume, 5.3 ± 3.1 mL vs. 2.9 ± 2.1 mL, respectively; number of cortex chips: 21.3 ± 8.1 vs. 15.2 ± 7.1, respectively). The reduction in the estimated ovarian reserve ranged from 10% to 20% in children to around 30% in adolescent girls (>10 years). CONCLUSION(S): Girls under the age of 10 tolerate a gonadotoxic insult better than adolescents, who may experience up to a 30% reduction in the ovarian reserve via first-line gonadotoxic treatment, which at present is considered to have little effect on the follicle pool. This information will improve counseling of young female cancer patients in deciding whether to undergo fertility preservation treatment.

A description of clinician reported diagnosis of type 2 diabetes and other non-type 1 diabetes included in a large international multicentered pediatric diabetes registry (SWEET).

BACKGROUND: Although type 1 diabetes (T1D) remains the most frequent form of diabetes in individuals aged less than 20 years at onset, other forms of diabetes are being increasingly recognized. OBJECTIVES: To describe the population of children with other forms of diabetes (non-type 1) included in the multinational SWEET (Better control in Pediatric and Adolescent diabeteS: Working to crEate CEnTers of Reference) database for children with diabetes. METHODS: Cases entered in the SWEET database are identified by their physician as T1D, type 2 diabetes (T2D) and other types of diabetes according to the ISPAD classification. Etiologic subgroups are provided for other types of diabetes. Descriptive analyses were tabulated for age at onset, gender, daily insulin doses, and hemoglobin A1c (A1C) for each type and subtype of diabetes and when possible, values were compared. RESULTS: Of the 27 104 patients included in this report, 95.5% have T1D, 1.3% T2D, and 3.2% other forms of diabetes. The two most frequent etiologies for other forms of diabetes were maturity onset diabetes of the young (MODY) (n = 351) and cystic fibrosis-related diabetes (CFRD) (n = 193). The cause was unknown or unreported in 10% of other forms of diabetes. Compared with T1D, children with T2D and CFRD were diagnosed at an older age, took less insulin and had lower A1C (all P < .0001). CONCLUSION: In centers included in SWEET, forms of diabetes other than type 1 remain rare and at times difficult to characterize. Sharing clinical information and outcome between SWEET centers on those rare forms of diabetes has the potential to improve management and outcome.

Heart defects and other features of the 22q11 distal deletion syndrome.

22q11.2 distal deletion syndrome is distinct from the common 22q11.2 deletion syndrome and caused by microdeletions localized adjacent to the common 22q11 deletion at its telomeric end. Most distal deletions of 22q11 extend from LCR22-4 to an LCR in the range LCR22-5 to LCR22-8. We present three patients with 22q11 distal deletions, of whom two have complex congenital heart malformation, thus broadening the phenotypic spectrum. We compare cardiac malformations reported in 22q11 distal deletion to those reported in the common 22q11 deletion syndrome. We also review the literature for patients with 22q11 distal deletions, and discuss the possible roles of haploinsufficiency of the MAPK1 gene. We find the most frequent features in 22q11 distal deletion to be developmental delay or learning disability, short stature, microcephalus, premature birth with low birth weight, and congenital heart malformation ranging from minor anomalies to complex malformations. Behavioral problems are also seen in a substantial portion of patients. The following dysmorphic features are relatively common: smooth philtrum, abnormally structured ears, cleft palate/bifid uvula, micro-/retrognathia, upslanting palpebral fissures, thin upper lip, and ear tags. Very distal deletions including region LCR22-6 to LCR22-7 encompassing the SMARCB1-gene are associated with an increased risk of malignant rhabdoid tumors.

Case report: stimulation of puberty in a girl with chemo- and radiation therapy induced ovarian failure by transplantation of a small part of her frozen/thawed ovarian tissue.

AIM OF THE STUDY: To induce puberty by transplantation of frozen/thawed ovarian tissue collected prior to gonadotoxic treatment for a cancer. PATIENTS AND METHODS: A 9-year-old girl with Ewing sarcoma had one ovary excised and cryopreserved prior to chemo- and radiotherapy. Functional activity of the remaining ovary was destroyed during treatment. Four and a half years later the girl remained pre-pubertal with postmenopausal levels of FSH. Two of ten pieces of frozen/thawed cortex were transplanted to the remaining ovary in order to stimulate puberty. RESULTS: Four months after the transplantation FSH returned to low levels. During the following year puberty gradually progressed to Tanner stage B4 and P3 and regular menstrual cycles started. However, after 19 months the function of the graft ceased. CONCLUSIONS: We have shown for the first time in a girl treated for cancer that transplanted ovarian tissue can regain function and secrete estradiol in a sufficient amount to induce puberty. In addition, the majority of her ovarian tissue remains frozen with a possibility to support fertility in adult life.

Further delineation of 17p13.3 microdeletion involving CRK. The effect of growth hormone treatment.

Recently, a 17p13.3 microdeletion syndrome characterized by significant postnatal growth retardation, mild to moderate mental retardation and facial dysmorphic manifestations has been delineated to a small region within the area of the Miller-Dieker syndrome critical region. We report a boy with a 284 kb deletion within the Miller-Dieker critical region including CRK, but not involving YWHAE and TUSC5. He showed mental retardation and had significant postnatal growth retardation. Further, he had slight facial and limb abnormalities. Cerebral MRI, including visualization of the pituitary gland, disclosed no abnormalities. The findings in the present case indicate, that CRK may also be involved in the facial phenotype of the 17p13.3 microdeletion syndrome, and that CRK, and not YWHAE, seems to be involved in limb malformations. The effect of growth hormone treatment in CRK-deficient children is discussed.

Clinical impact of corticosteroid-induced adrenal suppression during treatment for acute lymphoblastic leukemia in children: a prospective observational study using the low-dose adrenocorticotropin test.

OBJECTIVES: To investigate how frequently adrenal function fails to recover after corticosteroid therapy in children with acute lymphoblastic leukemia and to explore the clinical impact of slow adrenal recovery without steroid substitution. STUDY DESIGN: Low-dose (1 microg) adrenocorticotropic hormone tests were performed before and after steroid courses and during infectious episodes in 24 children. Test results were not available during the study. RESULTS: All 13 patients tested before treatment had normal adrenal responses. Adrenal suppression was found in 8 (47%) of 17 patients 5 days after discontinuation of a 5-week induction course of prednisolone and in 1 (20%) of 5 patients 7 days after a 3-week intensification course of dexamethasone, both courses being tapered over 9 days, as well as in all 13 patients tested 2 days after a 1-week prednisolone course. Clinically significant manifestations of adrenal suppression were noted in 3 (12%) patients. Of 204 scheduled tests, 131 were performed. CONCLUSIONS: High-dose glucocorticoid therapy may cause adrenal suppression lasting more than 1 week in children with acute lymphoblastic leukemia, even after tapering the dose. We suggest steroid replacement during stress episodes within 1 to 2 weeks after discontinuation and thereafter testing adrenal function selectively in accordance with symptoms.

Optic nerve size evaluated by magnetic resonance imaging in children with optic nerve hypoplasia, multiple pituitary hormone deficiency, isolated growth hormone deficiency, and idiopathic short stature.

OBJECTIVE: To objectively define criteria for intracranial optic nerve (ON) size in ON hypoplasia (ONH) on magnetic resonance imaging (MRI) scans. STUDY DESIGN: Intracranial ON sizes from MRI were compared between 46 children with ONH diagnosed by ophthalmoscopy (group 1, isolated ONH, 8 children; and group 2, ONH associated with abnormalities of the hypothalamic-pituitary axis and septum pellucidum, 38 children) and children with multiple pituitary hormone deficiency (group 3, multiple pituitary hormone deficiency, 14 children), isolated growth hormone deficiency (group 4, isolated growth hormone deficiency, 15 children), and idiopathic short stature (group 5, idiopathic short stature, 10 children). Intracranial ON size was determined by the cross-sectional area, calculated as [pi x (1/2) height x (1/2) width]. RESULTS: Groups 1 and 2 had lower intracranial ON size than did groups 3, 4, and 5 (P < .001). No patients in groups 3 through 5 who had MRI after 12 months of age (when 95% adult size of ONs is attained) had ONs <2.9 mm 2 . Visual acuity correlated significantly with ON size (P < .01). CONCLUSIONS: Magnetic resonance imaging of the ONs with cross-sectional area <2.9 mm 2 in a short child more than 12 months of age, with or without hypothalamic-pituitary axis abnormalities, confirms the clinical diagnosis of ONH.