Quá chênh lệch nhau bất hoạt nhiễm sắc thể X là phổ biến và rất quan trọng để biểu hiện bệnh, như các tế bào với X bất thường kích hoạt được thay thế bởi các tế bào với kích hoạt bình thường X (66,65) Intrafamilial biến đổi là nguyên tắc. tiêu biểu da | 132 NEUROLOGIC DISEASE IN WOMEN with male lethality but affected males have survived with subsequent father to daughter transmission possible 61 62 . Familial incontinentia pigmenti is due to mutations in the NEMO gene nuclear factor kB essential modulator at Xq28 8 . This gene produces a transcription factor that regulates multiple genes in immune inflammatory and apoptotic pathways 8 7 . Seventy to eighty percent of patients have an identical large genomic deletion 7 8 . Milder mutations occur and may produce surviving males 63 . There has been considerable debate over a second nonfamilial incontinentia pigmenti site at Xp11. Sybert 64 and Berlin 65 suggest that these patients do not satisfy the criteria for incontinentia pig-menti. Extremely skewed X chromosome inactivation is common and crucial to disease expression as cells with the abnormal X activated are replaced by cells with the normal X activated 66 65 Intrafamilial variability is the rule. Typical skin lesions progress through stages with initial blistering blisters pustules and erythema presenting in a typically linear distribution up to 4 months of age followed by verrucous and hyperkeratotic lesions up to 6 months of age Figure . These early lesions occur primarily on the extremities and are found at birth in 40 of patients they occur in almost 95 of cases 67 . In an individual patient not all stages may occur or some may occur simultaneously. Later affected women develop truncal hyperpigmentation often following Blaschko s lines developmental skin pattern due to proliferation of two different clonal cell lines during early embryogenesis up to 20 years of age and pale hairless patches of skin adulthood . Dental anomalies occur in 65 and features include delayed eruption and dental malformations. Conical and pegged teeth are the most common findings 67 . Ocular manifestations retinal vascular abnormalities with secondary retinal detachment may be absent or severe enough to cause visual loss 68 . .
