A autosomal recessive disorder caused by mutation in SLC19A2 gene and characterized by megaloblastic anemia, diabetes mellitus and sensorineural hearing loss. This child responds to which nutrient
This is Thiamine Responsive Megaloblastic syndrome:

It occurs due to mutation of SLC19A2 gene, encoding thiamine transporter protein, Leading to abnormal thiamine transportation.

Clinical features:

Megaloblastic anemia
Diabetes mellitus
Sensorineural hearing loss.
Vitamin B12
Vitamin c
Vitamin B1
Folic acid