Development of disease-specific growth charts in Turner syndrome and Noonan syndrome

Sex non-specific growth charts and potential clinical implications in the care of transgender youth

Introduction

The Centers for Disease Control and Prevention (CDC) and World Health Organization (WHO) created separate growth charts for girls and boys because growth patterns and rates differ between sexes. However, scenarios exist in which this dichotomizing "girls versus boys" approach may not be ideal, including the care of non-binary youth or transgender youth undergoing transitions consistent with their gender identity. There is therefore a need for growth charts that age smooth differences in pubertal timing between sexes to determine how youth are growing as "children" versus "girls or boys" (e.g., age- and sex-neutral, compared to age- and sex-specific, growth charts).

Methods

Employing similar statistical techniques and datasets used to create the CDC 2000 growth charts, we developed age-adjusted, sex non-specific growth charts for height, weight, and body mass index (BMI), and z-score calculators for these parameters. Specifically, these were created using anthropometric data from five US cross-sectional studies including National Health Examination Surveys II-III and National Health and Nutrition Examination Surveys I-III. To illustrate contemporary clinical practice, we overlaid our charts on CDC 2000 girls and boys growth charts.

Results

39,119 youth 2-20 years old (49.5% female; 66.7% non-Hispanic White; 21.7% non-Hispanic Black) were included in the development of our growth charts, reference ranges, and z-score calculators. Respective curves were largely superimposable through around 10 years of age after which, coinciding with pubertal onset timing, differences became more apparent.

Discussion

We conclude that age-adjusted, sex non-specific growth charts may be used in clinical situations such as transgender youth in which standard "girls versus boys" growth charts are not ideal. Until longitudinal auxological data are available in these populations, our growth charts may help to assess a transgender youth's growth trajectory and weight classification, and expectations surrounding these.

Adult Height in Indian Girls with Turner Syndrome Treated with Long-Term Growth Hormone Therapy - A Western India Tertiary Centre Experience

Background and Objectives

Owing to paucity of data on adult height in Indian girls with Turner syndrome treated with growth hormone (GH), this study was conducted to assess improvement in height following GH therapy and adult height achieved with long-term GH therapy in Indian girls with Turner syndrome and to assess relationship between achieved and predicted height.

Methodology

Retrospective analysis was performed on 12 girls with karyotype-proven Turner syndrome, who had attained adult height following mean duration of GH therapy of 4.8 years (range: 2.7-7.6). Adult height predictions were performed using index of responsiveness (IOR) and Ranke's prediction model.

Results

Mean age at starting GH was 10.2 ± 1.9 years; Pubertal induction was between 11 and 15 years. Mean height gain was 29.3 ± 9.8 cm (range: 14-39.5) from onset of treatment to adult height. Significant improvement in height Z scores (IAP 2015 and Indian Turner reference data) following GH therapy (p = 0.002 and 0.012, respectively) was noted. Using Indian Turner reference data, the height Z score improved from pre-treatment 0.8 ± 0.8 to 2.0 ± 0.9 on stopping GH and adult height Z score of 1.3 ± 0.7. Using Ranke's equation for prediction of near adult height, predicted and achieved adult height showed a strong positive correlation (Spearman correlation coefficient = 0.827, significant at 0.01 level).

Conclusion

At a dose in the lower range (40-50 mcg/kg/day) of recommendation and duration of 5 years, Indian girls with Turner syndrome can achieve adult height within the healthy Indian reference range. Dose individualization based on IOR would help in optimizing GH dosage and would turn out to be economically sustainable without compromising on height outcomes.

The past, present, and future of child growth monitoring: A review and primer for clinical genetics

Child growth measurements are critical vital signs to track, with every individual child growth curve potentially revealing a story about a child's health and well-being. Simply put, every baby born requires basic building blocks to grow and thrive: proper nutrition, love and care, and medical health. To ensure that every child who is missing one of these vital aspects is identified, growth is traditionally measured at birth and each well-child visit. While the blue and pink growth curves appear omnipresent in pediatric clinics, it is surprising to realize that their use only became standard of care in 1977 when the National Center for Health Statistics (NCHS) adopted the growth curve as a clinical tool for health. Behind this practice lies a socioeconomically, culturally, and politically complex interplay of individuals and institutions around the world. In this review, we highlight the often forgotten past, current state of practice, and future potential of this powerful clinical tool: the growth reference chart, with a particular focus on clinical genetics practice. The goal of this article is to understand ongoing work in the field of anthropometry (the scientific study of human measurements) and its direct impact on modern pediatric and genetic patient care.

Growth in girls with Turner syndrome

Turner syndrome (TS) is a chromosomal disorder affecting females characterized by short stature and gonadal dysgenesis. Untreated girls with TS reportedly are approximately 20-cm shorter than normal girls within their respective populations. The growth patterns of girls with TS also differ from those of the general population. They are born a little smaller than the normal population possibly due to a mild developmental delay in the uterus. After birth, their growth velocity declines sharply until 2 years of age, then continues to decline gradually until the pubertal age of normal children and then drops drastically around the pubertal period of normal children because of the lack of a pubertal spurt. After puberty, their growth velocity increases a little because of the lack of epiphyseal closure. A secular trend in height growth has been observed in girls with TS so growth in excess of the secular trend should be used wherever available in evaluating the growth in these girls. Growth hormone (GH) has been used to accelerate growth and is known to increase adult height. Estrogen replacement treatment is also necessary for most girls with TS because of hypergonadotropic hypogonadism. Therefore, both GH therapy and estrogen replacement treatment are essential in girls with TS. An optimal treatment should be determined considering both GH treatment and age-appropriate induction of puberty. In this review, we discuss the growth in girls with TS, including overall growth, pubertal growth, the secular trend, growth-promoting treatment, and sex hormone replacement treatment.

Blindness Secondary to Orbital Giant Cell Granuloma Mass-Effect in Noonan Syndrome With Return of Vision Following Surgical Decompression

ABSTRACT

Noonan syndrome is a rare, autosomal dominant disorder encompassing multiple congenital defects, as well as association with solid tumor and lesion development. The authors present a 26-year-old female with known Noonan syndrome and ongoing complaint of worsening unilateral vision, progressing to vision loss due to lesion mass effect. Decompressive surgery was performed, restoring patient's vision to baseline immediately postoperative. The lesion was confirmed to be giant cell granuloma. In this paper we discuss the unique presentation of vision loss due to orbital giant cell granuloma in Noonan syndrome with postoperative return of vision; the importance of a multi-disciplinary team evaluation, thorough preoperative clinical and image-based work up, intraoperative findings, postoperative outcome, and complexity of definitive management.