ABSTRACT
Mardini–Nyhan or LACHT (lung anomaly, congenital heart defect, and
thumb anomaly) syndrome is extremely rare. The literature contains only
12 reported cases in the pediatric population. We herein describe an
adult patient with this syndrome.
A 52-year-old woman was referred to our center for the closure of an
atrial septal defect (ASD), which had been discovered during evaluation
for chronic mild dyspnea and an abnormal electrocardiogram (ECG).
The patient had no prominent past medical history. Poor R-wave
progression with incomplete right bundle branch block in ECG prompted
further evaluation for associated cardiac anomalies and the possibility
of ASD device closure.
Transesophageal echocardiography showed a moderate-sized ASD (Panel A),
mild right ventricular enlargement, increased systolic pulmonary artery
pressure (≈ 50 mm Hg), and normal right pulmonary venous drainage;
however, the left pulmonary veins were not visible.
Chest X-ray unexpectedly showed total agenesis of the left lung,
increased cardiothoracic ratio, the shifting of the heart and the
mediastinum to the left side, and the upward displacement of the left
diaphragm (Panel B).
Cardiac computed tomography confirmed the chest X-ray findings by
illustrating agenesis of the left main bronchus from the proximal part,
complete agenesis of the left lung (Panel C), a large secundum ASD
(Panel D), dilatation of the main pulmonary artery (red arrow) and the
right main pulmonary artery (yellow arrow), and absence of the left main
pulmonary artery (Panel E & Panel F).
Heart catheterization for an accurate evaluation of pulmonary
hypertension demonstrated mild hypertension (pulmonary artery pressure =
55 mm Hg). Pulmonary artery injection showed dilated main and right
pulmonary arteries without a visible left-sided branch (Panel G & Panel
I). Further evaluation revealed congenital left thumb hypoplasia. Hand
X-ray illustrated a hypoplastic left first metacarpal (Panel H).
All the mentioned findings indicated a syndromic manifestation, termed
“lung anomaly, congenital heart defect, and thumb anomaly (LACHT)” or
Mardini-Nyhan syndrome. 1