Incontinentia pigmenti in boys: Causes and consequences

Incontinentia pigmenti with intracranial arachnoid cyst: A case report

BACKGROUND

Incontinentia pigmenti (IP) is a rare X-linked dominant genetic disorder that can be fatal in male infants. It is a disease that affects many systems of the human body. In addition to characteristic skin changes, patients may also have pathological features of the eyes, teeth, and central nervous system. Therefore, the lesions in these systems may be the first symptoms for which patients seek treatment. To date, no cases of IP complicated by intracranial arachnoid cyst (IAC) have been reported. This paper aims to report a case of IP with IAC in order to share the diagnosis and treatment experience of this rare case with other clinicians.

CASE SUMMARY

An 11-year-old female patient suffered intermittent limb convulsions for five months and was sent to hospital. In the initial stage, the patient was considered to have primary epilepsy. Further investigation of the patient's medical history, physical examination and imaging examination led to the diagnosis of IP combined with intracranial space-occupying lesions, and secondary epilepsy. The patient was treated with craniotomy, and postoperative pathology revealed an IAC. The patient recovered well after craniotomy and had no obvious surgery-related complications. During the follow-up period, the patient did not have recurrent epilepsy symptoms.

CONCLUSION

IP is a multi-system disease that presents with typical skin lesions at birth, but the long-term prognosis of this disease depends on the involvement of systems other than the skin, especially nervous system and ocular lesions.

Human Genetic Diseases Linked to the Absence of NEMO: An Obligatory Somatic Mosaic Disorder in Male

De novo somatic mutations are well documented in diseases such as neoplasia but are rarely reported in rare diseases. Hovewer, severe genetic diseases that are not compatible with embryonic development are caused exclusively by deleterious mutations that could only be found as mosaic and not as inherited mutations. We will review here the paradigmatic case of Incontinentia Pigmenti, a rare X-linked dominant disease caused by deficiency of the NEMO (also called IKKgamma) protein, which plays a pivotal role in tissue homeostasis. The loss-of-function mutations of NEMO are embryonically lethal in males while females survive because of unbalanced X-inactivation due to NEMO wild type (WT) expressing cells survival despite of NEMO mutant expressing cells. The few surviving IP males are obligatory mosaic mutants with the typical clinical presentation of IP in female. Indeed, the IP pathogenesis in the female and most likely also in the male somatic mosaics is based on the cellular effects of an impaired NEMO activity, but in the context of the interaction of genetically different cells in the affected tissue, which might underline the inflammatory status.