Bacterial heat-stable enterotoxins: translation of pathogenic peptides into novel targeted diagnostics and therapeutics

Heat-stable toxins (STs) produced by enterotoxigenic bacteria cause endemic and traveler’s diarrhea by binding to and activating the intestinal receptor guanylyl cyclase C (GC-C). Advances in understanding the biology of GC-C have extended ST from a diarrheagenic peptide to a novel therapeutic agent. Here, we summarize the physiological and pathophysiological role of GC-C in fluid-electrolyte regulation and intestinal crypt-villus homeostasis, as well as describe translational opportunities offered by STs, reflecting the unique characteristics of GC-C, in treating irritable bowel syndrome and chronic constipation, and in preventing and treating colorectal cancer.

Cantú Syndrome With Acromegaloid Features, Multiple Endocrinopathies, and Infection Susceptibility

Cantú syndrome involves fetal polyhydramniosis, congenital hypertrichosis, and macrosomia. Distinctive features include acromegaloid features with broad nasal bridge and macroglossia as well as cardiac abnormalities, including patent ductus arteriosus. We present a case in a male patient, who presented with cardiac abnormalities in childhood, but was diagnosed with the syndrome in adulthood after many years of atypical symptoms such as multiple endocrinopathies and infection susceptibility. He had surgery for a patent ductus arteriosus in early childhood. During adulthood, he developed idiopathic pericarditis. Extensive rheumatological investigations were made, and in parallel, several endocrinopathies were found. These included thyroiditis with subsequent hypothyroidism, idiopathic partial hypocortisolism, and GH insufficiency. In addition, he had mild neutropenia and required hospitalization twice because of Streptococcus pyogenes infections. Immunodeficiency screening has not revealed a specific primary immunodeficiency, yet transient neutropenia, low count of CD8+ effector memory T cells, as well as lymphocyte responses, was seen during bacteremia. The diagnose was made after a trio-whole genome sequencing identified a pathogenic missense variant of the gene ABCC9 (c.3460C > T;p. (Arg1154Trp)) causing Cantú syndrome.