Cantu syndrome and hypopituitarism: implications for endocrine monitoring

Abstract

Summary: Cantu syndrome, or hypertrichotic osteochondrodysplasia, is a rare, autosomal dominant genetically heterogeneous disorder. It is characterized by hypertrichosis, cardiac and skeletal anomalies and distinctive coarse facial features. We report a case where slowed growth velocity at 13 years led to identification of multiple pituitary hormone deficiencies. This adds to other reports of pituitary abnormalities in this condition and supports inclusion of endocrine monitoring in the clinical surveillance of patients with Cantu syndrome.

Learning points: Cantu syndrome is a rare genetic disorder caused by pathogenic variants in the ABCC9 and KCNJ8 genes, which result in gain of function of the SUR2 or Kir6.1 subunits of widely expressed KATP channels. The main manifestations of the syndrome are varied, but most commonly include hypertrichosis, macrosomia, macrocephaly, coarse 'acromegaloid' facies, and a range of cardiac defects. Anterior pituitary dysfunction may be implicated in this disorder, and we propose that routine screening should be included in the clinical and biochemical surveillance of patients with Cantu syndrome.

Keywords: 2019; ACTH; ACTH stimulation; Adolescent/young adult; Adrenal insufficiency; Bone age; Buserelin stimulation*; Cantu syndrome*; Cardiac malformations; Cardiology; Cortisol; Cortisol (plasma); Electrocardiogram; Face - coarse features; Fatigue; GH; Genetics; Glucocorticoids; Growth retardation; Heart failure; Heart murmur; Hydrocortisone; Hypertrichosis; Hypopituitarism; IGF1; MRI; Male; Molecular genetic analysis; New Zealand; November; Paediatrics; Pituitary; Prolactin; Tanner scale; Testosterone; Unique/unexpected symptoms or presentations of a disease; White; X-ray.

Figure 1

Electronic growth chart (Z-scores and graphs based on WHO child growth standards). Red arrow indicates point of growth hormone commencement. Red x – mid parental height estimate.

Figure 2

X-ray of left hand used for determination of bone age in the patient.

Figure 3

T1-weighted MRI sections demonstrating a small pituitary gland, with normal architecture (A: sagittal section, B: coronal section). White arrow indicates pituitary gland in pituitary fossa (Panel A) and in panel B indicates pituitary stalk.