Treatable Cause of Pancytopenia, Recurrent Infections and Refractory Epilepsy: Secondary to Hereditary Folate Malabsorption (HFM) Due to Novel Pathogenic Variant.

Hereditary folate malabsorption (HFM) is a rare disorder of proton-coupled folate transporter deficiency. It is characterized by macrocytic anemia, recurrent infections, and epilepsy. A five-year-old girl presented with recurrent pneumonia, diarrhea, and mouth ulcers. On examination, pallor, microcephaly with spastic quadriparesis was noted. On investigations, leukopenia and thrombocytopenia with megaloblastic bone marrow picture and low folate levels was found. HFM was diagnosed at two years of age and the child was treated with folinic acid. Her diagnosis was confirmed by whole-exome sequencing which revealed a novel pathogenic homozygous frameshift insertion variation (c.620dupG) in the exon 2 of the SLC46A1 gene which was further confirmed by Sanger sequencing. The child improved significantly except for a partial improvement in neurological symptoms.