Menkes disease is a congenital disorder caused by changes in copper metabolism derived from mutations in the ATP7A gene. It is characterized by physical and neurological alterations. In the neonatal period, these alterations can be nonspecific, which makes early diagnosis a challenge. Diagnosis can be suspected when there are low levels of ceruloplasmin and serum copper. Molecular analysis confirms the diagnosis. Treatment is parenteral administration of copper histidine. We report a familial case with molecular confirmation. The proband had clinical and biochemical suspicious. Treatment with copper histidine was indicated, but initiated at the age of 2 months and 27 days only. He did not present improvements and died at 6 months. The mother became pregnant again, a male fetus was identified and copper histidine was manufactured during pregnancy. He was born healthy, biochemical markers were reduced and treatment was indicated. Molecular analysis was performed confirming mutation in both the mother and the proband, while the other son did not have mutation, so treatment was discontinued. We support the clinical relevance of molecular confirmation for the correct diagnosis and genetic counseling, once clinical findings in the neonatal period are nonspecific and early treatment with parenteral copper histidine must be indicated.