A 30-year-old female who's diagnosed with classical HCU in early childhood based on clinical and biochemical findings. She has a marfanoid habitus, bilateral lens subluxation with a history of left eye lensectomy and intraocular lens implant, and mild mental retardation. In addition to a blood methionine level of 1010 mumol/L and homocysteine level of 180 mumol/. She has been on regular follow-ups at a specialized metabolic clinic since childhood but had a poor diet and medications compliance. Her family history is remarkable for classical HCU in her younger brother; however, no family history of Bronchiectasis.
The patient has had a chronic cough with multiple episodes of wheezes and lower respiratory tract infections for several months. She was initially evaluated at a general medicine clinic with multiple chest x-rays (CXR) and several failed attempts of spirometry as she couldn't do it optimally. Subsequently, she was treated for possible Bronchial Asthma with a trial of inhalers (fluticasone/formoterol with as-needed salbutamol) and referred to a Pulmonology clinic. Eventually, she was evaluated at a Pulmonology clinic, and at that time, she had stopped taking her inhalers as they were ineffective. Clinically, she complained of chronic productive cough with thick greenish sputum, which she had difficulty clearing out, associated with occasional wheezes and mild exertional shortness of breath. She had no history of fever, night sweats, weight loss, hemoptysis, or features of allergic rhinitis, and no symptoms of gastroesophageal reflux disease (GERD). She is a lifetime non-smoker with good social support. She was comfortable and maintained 100% oxygen saturation on room air on examination. She had no clubbing or cyanosis, and her chest examination was remarkable for mild right basal coarse crackles.
A computed tomography (CT) scan of the chest revealed abnormally dilated trachea and both main bronchi, along with bronchiectasis over both lung fields. In addition to a single minimal emphysematous lesion. Otherwise, the rest of the lung fields were unremarkable. (Fig. 1). In light of these radiological findings, the diagnosis of Mounier-Kuhn Syndrome was made, and bronchiectasis work-up was initiated to rule out other causes. Blood tests, including complete blood count with differential, immunoglobulins level, autoimmune panel, total IgE level, and Aspergillus fumigatus specific IgE, were all within normal limits. In addition, sputum culture showed moderate growth of sensitive Haemophilus Influenzae; otherwise, negative Mycobacterial and fungal cultures. At this point, the patient was diagnosed with TBM (Mounier-Kuhn Syndrome) and bronchiectasis secondary to HCU. She was started on a multidisciplinary management approach, including dietitian support (with the collaboration of the metabolic team), chest physiotherapy, sputum clearing techniques, appropriate vaccinations, and regular follow-up.