Loeys–Dietz Syndrome and Its Connection to Allergies and Hyper-IgE

Introduction Loeys–Dietz syndrome is a genetic disorder caused by mutations in TGFBR1 and TGFBR2, inherited in an autosomal dominant pattern, primarily affecting connective tissue. It is characterized by the development of aneurysms, cleft palate or bifid uvula, and long extremities. It has also been associated with a higher predisposition to allergic diseases and inflammatory gastrointestinal disorders. Case Presentation A 5-year-old male preschool patient. Notable history includes threatened miscarriage at the third month of gestation and lack of progress during delivery. He was diagnosed with Loeys–Dietz syndrome by the genetics department, with a pathogenic heterozygous variant in TGFBR2 c.1610G>C (p.Arg537Pro). He was referred to our clinic due to multiple episodes of sinusitis treated by ENT without full improvement. Laboratory tests showed blood eosinophils at 530 cells/µL, nasal mucus eosinophils at 40%, and total IgE of 322 IU/mL. Skin prick testing was positive for Fraxinus, Dermatophagoides farinae, and Dermatophagoides pteronyssinus. Treatment was initiated with specific immunotherapy, antihistamines, and antileukotrienes. The patient experienced a 90% improvement with specific immunotherapy and has not had further infections. Discussion Loeys–Dietz syndrome is a genetic disorder affecting the TGF-β receptor. The literature reports an up to 30% higher prevalence of allergic diseases compared to general population, along with allergic gastrointestinal inflammation, including eosinophilic esophagitis and inflammatory bowel disease. Conclusion This is a condition in which certain symptoms may go unnoticed or undervalued; however, these patients can progress to asthma, exhibit hyper-IgE syndrome symptoms, and even develop inflammatory bowel disease in adulthood. Therefore, proper follow-up and timely treatment are essential.