Rare co-existence of 15q26 deletion syndrome and lymphangioleiomyomatosis: diagnostic and therapeutic challenge.

15q26 deletion syndrome is a rare genetic condition caused by the deletion of terminal end of the long arm of chromosome 15 (Drayer's syndrome). Clinical presentation usually implies intrauterine growth restriction, postnatal growth failure, varying degrees of intellectual disability, developmental delay, typical facial appearance, brachydactyly and diaphragmatic hernia. Lymphangioleiomiomatosis (LAM) is a rare genetic disease affecting multiple organs, which almost exclusively afflicts women. Typical presentation of LAM disease is pulmonary LAM, characterized by cyst-like destruction of pulmonary tissue, which leads to loss of pulmonary function, and if progresses further can lead to recurring pneumothoraxes. Co-existence of these two rare diseases hasn't been reported so far. Here we report a case of the simultaneous presence of 15q26 deletion syndrome and LAM disease in a 38-year-old female. She presented with short statue, brachydactyly, pes equinovarus, microcephaly and signs of intellectual disability manifesting from birth and early childhood. At the age of 23 she starts to suffer of recurring pneumothoraxes with gradual loss of pulmonary function. CT and pathohistological findings revealed the presence of pulmonary LAM and genetic testing revealed 15q26.2 microdeletion characteristic for 15q26 deletion syndrome. Successful treatment of LAM using mTOR inhibitor Sirolimus resulted in clinical and functional improvement.