Mrs A is hesitant about having children because her two sisters had sons who had died from kinky hair disease. Her mother's brother also died of the same condition. What is the mode of inheritance of kinky hair disease which is running in this family?

Menkes syndrome is an X linked recessive disorder characterized by a mutation in ATP7a or MNK gene encoding copper binding ATPase leading to deficient copper transpo and metabolism with subsequently low serum copper. Pili tori is the most common hair manifestation, showing flattening and twisting at 180 degree angles. Children show progressive neurologic degeneration with mental retardation, failure to thrive and hypotonia. X-linked Recessive disease is seen only in males because males have only one X chromosome. There is no male to male transmission. Heterozygous females are clinically normal but may be detected by subtle clinical features. Ref: Embryology By Ronald W. Dudek, 3rd Edition, Page 229 ; The Busy Physician's Guide to Genetics, Genomics and Personalized Medicine By Kevin M. Sweet, Page 41; Clinical Genetics In Nursing Practice By Felissa R. Lashley 3rd Edition ; Dermatology Terminology By Herbe B. Allen, Page 100