Incontinentia pigmenti with encephalocele in a neonate: a rare association

The Impact of the IKBKG Gene on the Appearance of the Corpus Callosum Abnormalities in Incontinentia Pigmenti

Incontinentia pigmenti (IP) is a rare skin disease combined with anomalies of the teeth, eyes, and central nervous system (CNS). Mutations of the IKBKG gene are responsible for IP. Among the most frequent CNS abnormalities found in IP using magnetic resonance imaging (MRI) are corpus callosum (CC) abnormalities. The aim of the study was to determine the presence of CC abnormalities, their relationship with the IKBKG mutations, and the possible presence of mutations of other genes. A group of seven IP patients was examined. Analyses of the IKBKG gene and the X-chromosome inactivation pattern were performed, as well as MRI and whole exome sequencing (WES) with the focus on the genes relevant for neurodegeneration. WES analysis showed IKBKG mutation in all examined patients. A patient who had a mutation of a gene other than IKBKG was excluded from further study. Four of the seven patients had clinically diagnosed CNS anomalies; two out of four had MRI-diagnosed CC anomalies. The simultaneous presence of IKBKG mutation and CC abnormalities and the absence of other mutations indicate that IKBKG may be the cause of CC abnormalities and should be included in the list of genes responsible for CC abnormalities.

Unilateral Cerebral Atrophy: Severe Neuroimaging Feature of Incontinentia Pigmenti without Acute Encephalopathic State

Incontinentia pigmenti (IP) is a rare X-linked multisystem disease caused because of mutation in the IKBKG (inhibitor of kappa-B kinase gamma, previously NEMO) gene. Involvement of central nervous system is seen in approximately one-third of these patients. Ischemic strokes, symptomatic seizures, and encephalopathy can be seen during neonatal or early infancy age group. Typically, early bilateral brain involvement is seen with periventricular white matter injury, hemorrhagic infarction, and multifocal cortical injury. We reported a patient who did not have early encephalopathic presentation, but presented with right hemiparesis and intellectual impairment. Magnetic resonance imaging of the brain revealed extensive left cerebral white matter volume loss and encephalomalacia with Wallerian degeneration of the left cortical spinal tract. This case highlights a rare presentation of unilateral cerebral atrophy with no definite episode of acute encephalopathy during infancy to suggest pure intrauterine injury. Microvascular occlusion, inflammatory cerebral vasculopathy, and recurrent silent strokes possibly produced this extensive neurologic manifestation antenatally. We also reviewed the complex pathogenic mechanisms involved in IP.

Incontinentia pigmenti

Incontinentia pigmenti is a rare genodermatosis in which the skin involvement occurs in all patients. Additionally, other ectodermal tissues may be affected, such as the central nervous system, eyes, hair, nails and teeth. The disease has a X-linked dominant inheritance pattern and is usually lethal to male fetuses. The dermatological findings occur in four successive phases, following the lines of Blaschko: First phase - vesicles on an erythematous base; second phase - verrucous hyperkeratotic lesions; third phase - hyperchromic spots and fourth phase - hypochromic atrophic lesions.