Elevated Head Circumference-to-Height Ratio Is an Early and Frequent Feature in Children with Neurofibromatosis Type 1

Abstract

Background/Aims: Children with neurofibromatosis type 1 (NF1) tend to be macrocephalic and short. Our aim was to define the incidence and diagnostic accuracy of elevated head circumference-to-height ratio (HCHR) in children with NF1 and to assess if elevated HCHR would facilitate early diagnosis of NF1. Methods: Retrospective analysis of growth and health data of 80 NF1 patients aged 0-7 years was performed. The incidence and diagnostic accuracy of elevated HCHR for NF1 was analyzed using receiver operating characteristic curves. Results: The median age when the first elevated (≥2.0 SDS) HCHR value was detected was 0.3 years (range 0.0-5.3). At the median age of diagnosis (3.6 years), 53.8% of NF1 children exhibited elevated HCHR. The diagnostic accuracy of HCHR alone was 0.78 (95% CI 0.72-0.84), but in comparison with the seven National Institutes of Health diagnostic criteria for NF1, elevated HCHR was the second most prevalent feature. Conclusion: Elevated HCHR is an early and frequent feature in NF1 children. Taking HCHR into account would facilitate the early detection of NF1.

Anthropometric characteristics and comorbidities in Japanese patients with neurofibromatosis type 1: A single institutional case–control study

“…There have been previous reports of an association between NF1 and short stature, and our results are consistent with these. In contrast, there have been two recent reports that NF1 patients with 17q11 microdeletion (deletion of the whole NF1 gene) were taller than general populations .…”

Endocrine Implications of Neurofibromatosis 1 in Childhood

“…The diagnostic accuracy of HCHR alone was 0.78 (95% CI 0.72-0.84). Considering the seven diagnostic criteria for NF1 (table 1), elevated HCHR was the second most common clinical manifestation after café au lait spots [10]. …”

Macrocephaly Is Not a Predictor of Optic Pathway Glioma Development or Treatment in Neurofibromatosis Type 1

“…Macrocephaly is one of the most common features of neurofibromatosis type 1, observed in approximately 50-75% of affected individuals. 9,16 In this setting, MRI studies have revealed that macrocephaly is associated with the enlargement of multiple brain structures, leading to increased cranial volumes and brain volumes. 17 As such, some reports have described relative increases in white matter volumes, specifically involving midline structures, like the corpus callosum and brainstem, 18 whereas others have described increased gray matter volumes.…”

“…Macrocephaly is one of the most commonly-observed clinical manifestations among individuals with neurofibromatosis type 1. 7 –9 It is defined as an age- and sex-adjusted occipital-frontal circumference greater than the 97th percentile or greater than 2.0 standard deviations above the mean. In the setting of neurofibromatosis type 1, macrocephaly usually has no obvious etiology, and likely represents an increase in brain volume as revealed by magnetic resonance imaging (MRI).…”