Prenatal Diagnosis of Infantile Neuroaxonal Dystrophy

Infantile Neuroaxonal Dystrophy (INAD1, MIM # 256600), is a rare autossomal recessive neurodegenerative disorder. The clinical picture is characterized by psychomotor regression and hypotonia, which progresses to spastic tetraplegia, visual impairment and dementia. Onset is within the first 2 years of life and death usually happens before the age of 10. In 2006, Morgan et al described that mutations in PLA2G6 gene localized in chromosome 22 (22q13), caused INAD1. Evidence showed that a large proportion of patients with infantile neuroaxonal dystrophy have a mutation in the PLA2G6 gene. A 36-years-old pregnant woman presented for obstetric follow up. It was the second pregnancy of this healthy, nonconsanguineous couple. Their 7 year-old daughter was affected with Infantile Neuroaxonal Dystrophy. Molecular testing was done in the child and, as a causal mutation was detected, it was possible to offer a specific prenatal diagnosis. The molecular study of PLA2G6 gene by amniocentesis showed the presence of a mutation in heterozygoty and the karyotype was normal for a female foetus. To our knowledge, this is the first molecular prenatal diagnosis of INAD1 in Portugal.