Leukodystrophies are a group of usually inherited disorders characterized by degeneration of the white matter in the brain. [1]. The leukodystrophies are caused by imperfect growth or development of the myelin sheath, the fatty insulating covering around nerve fibres. [2]. Metachromatic leukodystrophy is a rare hereditary (genetic) disorder that causes fatty substances (lipids) to build up in cells, particularly in the brain, spinal cord and peripheral nerves. This buildup is caused by a deficiency of an enzyme that helps break down lipids called sulfatides.

It includes three types of late infantile (< 4years of age), Juvenile (4- 16years of age), adult (> 16 years of age). Signs and symptoms may vary. The infantile form is the most common and progresses more rapidly than other forms. There is no cure for metachromatic leukodystrophy yet. Depending on the form and age of onset, early identification and treatment may help manage some signs and symptoms and delay the progression of the disorder.

We report a four-year-old male child born of the nonconsanguineous marriage, with presentation as of progressive loss of fully developed motor milestones in the form of inability to walk and sit since 8 months (regression of achieved motor milestones). The child has attained all developmental milestones as per age till 3 years of life and parents noticed gradual loss of achieved milestones thereafter.

The child was also not able to raise hands above the shoulder and hold or grasp things in hand. Head control, bowel and bladder control were lost. Speech abnormalities were present and the child was able to speak 2 words with meaning. There was a history of limb tightening, difficulty in chewing solid food and drooling of saliva. History of cyanotic spells present.

There was a history of the death of sons (4 out of 5) of paternal uncle 1 year after birth but no documents were available. The patient's antenatal history was uneventful with a birth weight of 3.6 kg and partially immunized till 1 year of life. On general examination we found the patient to be alert with a heart rate of 116 beats per minute, Blood pressure 98/48 mm Hg and oxygen saturation 97% and pallor were present.

MRI scanning reveals symmetric confluent areas with high signal strength in periventricular white matter with subcortical U fibre ranging. MRI is considered the primary imaging modality in patients with leukodystrophy and plays a role in recognizing, localizing, and characterizing anomalous white matter underlying it.[3]. There is no prescribed treatment for the disease. To minimize the symptoms of the subject and relieve discomfort, medications such as muscle relaxants, psychological medications, analgesics and epilepsy drugs, may be provided.[5]

To improve neurocognitive functions, bone marrow or cord blood transplantation is the solution available primarily in the case of asymptomatic late infantile and early juvenile forms. Future treatment options for the disease which include gene therapy, enzyme replacement therapy, substratum reduction therapy, and potentially enzyme enhancement therapy is currently being explored.[4].

MLD is a serious illness that gets worse over time. Individuals eventually lose all muscular and mental functions. The span of life varies depending on the age the condition started but the course of the disease usually runs from 3 to 20 years. The key to success is the right indications for both the doctor and the health professionals to reassure the patient throughout the entire course of treatment and to institute a strict and regular reminder regime to ensure a better prognosis.