Lymphedema complicated by protein-losing enteropathy with a 22q13.3 deletion and the potential role of CELSR1

22q13.3 deletion syndrome is a well-known syndrome characterized by typical clinical findings including neonatal hypotonia, absent or severely delayed speech, intellectual disability, and other various features, and detection of a heterozygous deletion of chromosome 22q13.3 with the involvement of at least part of SHANK3 . It is reported that 10% to 29% of patients with 22q13.3 deletion syndrome present lymphedema. Protein-losing enteropathy (PLE) has never been reported in 22q13.3 deletion syndrome. Patient concerns: The patient presented to our institution for refractory hypoalbuminemia and chronic lymphedema in both legs. Diagnosis: The patient manifested intellectual disability, absent speech, tooth grinding, dysmorphic face, and abnormal hands and toenails. Copy-number variation sequencing confirmed the maternal deletion in 22q13.31-q13.33 (chr22:46285592–51244566, hg19). The patient was genetically diagnosed with 22q13.3 deletion syndrome. Interventions: Low-fat diets and medium-chain triglycerides supplements were prescribed. The patient was recommended to wear compression garments and elevate legs. Outcomes: The symptom of diarrhea was resolved, but hypoalbuminemia persisted. Lower extremities lymphedema was gradually becoming severe. Conclusions: Primary lymphedema and PLE can occur simultaneously in a patient with 22q13.3 deletion syndrome. The 2 phenotypes could share the same genetic etiology of congenital lymphatic abnormalities. CELSR1 deletion may play a role in lymphatic dysplasia. The case also provides additional proof of the pathogenic effect of CELSR1 on hereditary lymphedema.