Familial segmental neurofibromatosis

The Clinical Spectrum of Mosaic Neurofibromatosis in Children and Adolescents

BACKGROUND

Segmental neurofibromatosis was initially described by Miller and Sparks (1977) as manifestations of neurofibromatosis limited to a dermatomal, localized distribution. Now termed mosaic neurofibromatosis, previous literature described this disease in children and adolescents with individual case reports and small-numbered case series. This study presents a large series of children and adolescents with mosaic neurofibromatosis.

METHODS

A retrospective chart review of a single institution medical record database was performed on all cases of mosaic neurofibromatosis diagnosed between the years 1998 and 2017. Eligible subjects were determined by 2 criteria: (1) segmental or unilateral expression of one of more signs of NF I according to those outlined in the NIH criteria and (2) were under 18 years of age at the time of diagnosis. Select information extracted include location of clinical features, NF manifestations (neurofibromas, plexiform neurofibromas, café-au-lait spots, freckling, Lisch nodules), presence of a diffuse area of cutaneous hyperpigmentation, and other significant medical conditions.

RESULTS

Sixty-eight cases met established criteria. Average age at diagnosis was 8.28 ± 4.47 years. Thirty-seven (54%) were male and 31 (46%) were female. Localization of the dermatologic manifestations is as follows: left side in 28 (41%) cases, right side in 32 (47%) cases, and bilateral in 8 (11%) cases. Café-au-lait lesions appeared in 64 (94%) of cases and 14 (21%) had axillary and inguinal freckling.

CONCLUSIONS

This study expands our understanding of the disease characteristics seen in children and adolescents with mosaic neurofibromatosis and confirms the need to focus on pigmentary changes in children with mosaic neurofibromatosis.

Hereditary segmental neurofibromatosis: a report of three cases in a family

Hereditary segmental neurofibromatosis (SNF) is an extremely rare form of SNF with nine families reported till date. SNF is considered to be a result of mosaicism and hereditary transmission is possibly explained by increased susceptibility of mutations at neurofibromatosis gene loci. We report here three members of an Indian family with SNF. Our index case, a 20-year-old woman had multiple soft to firm papules and nodules over right shoulder associated with severe intermittent pain. Her father had three similar nodules over left upper arm and elder sister had two such nodules over right upper arm. The father and elder sister were incidentally diagnosed and they had never sought medical advice considering their lesions to be a familial trait. In the absence of symptoms, many familial cases of SNF are missed thus making any systematic analysis to ascertain its genetic basis difficult.

Mosaic Neurofibromatosis Type 1: A Systematic Review

Confusion is widespread regarding segmental or mosaic neurofibromatosis type 1 (MNF1). Physicians should use the same terms and be aware of its comorbidities and risks. The objective of the current study was to identify and synthesize data for cases of MNF1 published from 1977 to 2012 to better understand its significance and associations. After a literature search in PubMed, we reviewed all available relevant articles and abstracted and synthetized the relevant clinical data about manifestations, associated findings, family history and genetic testing. We identified 111 articles reporting 320 individuals. Most had pigmentary changes or neurofibromas only. Individuals with pigmentary changes alone were identified at a younger age. Seventy-six percent had localized MNF1 restricted to one segment; the remainder had generalized MNF1. Of 157 case reports, 29% had complications associated with NF1. In one large case series, 6.5% had offspring with complete NF1. The terms "segmental" and "type V" neurofibromatosis should be abandoned, and the correct term, mosaic NF1 (MNF1), should be used. All individuals with suspected MNF1 should have a complete physical examination, genetic testing of blood and skin, counseling, and health surveillance.

Mosaic generalized neurofibromatosis 1: report of two cases

BACKGROUND

We report two cases of mosaic generalized neurofibromatosis 1 (NF1) and review the history of the classification of segmental neurofibromatosis (SNF; Ricardi type NF-V). Somatic mutations giving rise to limited disease, such as segmental neurofibromatosis are manifestations of mosaicism. If the mutation occurs before tissue differentiation, the clinical phenotype will be generalized disease. Mutations that occur later in development give rise to disease that is confined to a single region.

OBJECTIVES

Segmental neurofibromatosis is caused by a somatic mutation of neurofibromatosis type 1, and should not be regarded as a distinct entity from neurofibromatosis 1. Cases previously referred to as unilateral or bilateral segmental neurofibromatosis are now best referred to as mosaic generalized or mosaic localized neurofibromatosis 1.

A unique case of hereditary bilateral segmental neurofibromatosis on the face

Segmental neurofibromatosis is a rare clinical finding generally with no family history and facial involvement. There are four subtypes of segmental neurofibromatosis: true segmental, localized cases with deep involvement, hereditary segmental and bilateral segmental neurofibromatosis. Here we report three patients from the same family (father, son and granddaughter) with segmental bilateral neurofibromatosis on the face. This form has not been noticed in the literature.

Segmental neurofibromatosis: a report of 3 cases

Neurofibromatosis is a genetic disorder of neural crest-derived cells that primarily affect growth of neural tissues. It is broadly divided into three categories: (a) von Recklinghausen's neurofibromatosis or NF-1, (b) bilateral acoustic neuroma (NF-2), and (c) all other neurofibromatoses, including alternate or atypical forms of the disease. The patients with generalized form of NF1 are characterized by multiple café-au-lait spots and neurofibromas and diagnosed easily. But when an individual has small number of lesions in a limited region of the body it could be neglected by the patient or not be recognized by the clinicians as a segmental form of neurofibromatosis. We describe three cases of segmental neurofibromatosis (SNF). These cases have been classified as segmental NF according to Riccardi's definition of SNF and classification of neurofibromatosis. Segmental form of NF may evolve into a complete form over time. Also, this disorder may be transmitted to the offspring's of these individuals. Hence genetic counseling of these individuals must include these facts.

Giant café-au-lait macule in neurofibromatosis 1: a type 2 segmental manifestation of neurofibromatosis 1?

Type 2 segmental manifestation of autosomal dominant dermatoses refers to pronounced segmental lesions superimposed on the ordinary nonsegmental phenotype, indicating loss of heterozygosity occurring at an early stage of embryogenesis. We describe a 20-year-old Taiwanese woman with typical lesions of neurofibromatosis type 1 (NF1) in the form of characteristic café-au-lait spots, neurofibromas, axillary freckling and Lisch nodules. In addition, a giant garment-like or "bathing-trunk" café-au-lait macule involved the lower half of the trunk, the buttocks, and parts of the thighs, being superimposed on the ordinary smaller spots of NF1. This large café-au-lait macule may be best explained as an example of type 2 segmental NF1. A novel mutation (3009delG) in exon 23 was also identified in this patient, which has not yet been described in sporadic and familial NF1.

Neurofibromatosis type 1 in genetic counseling practice: recommendations of the National Society of Genetic Counselors

The objective of this document is to provide recommendations for the genetic counseling of patients and families undergoing evaluation for neurofibromatosis type 1 (NF1) or who have received a diagnosis of NF1. These recommendations are the opinions of a multi-center working group of genetic counselors with expertise in the care of individuals with NF1. These recommendations are based on the committee's clinical experiences, a review of pertinent English language medical articles, and reports of expert committees. These recommendations are not intended to dictate an exclusive course of management, nor does the use of such recommendations guarantee a particular outcome. These recommendations do not displace a health care provider's professional judgment based on the clinical circumstances of an individual patient.

Divided café-au-lait macule of the mouth

We describe a 4-year-old, otherwise healthy boy with a congenital history of a perioral and labial segmental café-au-lait macule, who was noted to have unilateral localized gingival hyperpigmentation that aligned with the café-au-lait macule. This case is highly illustrative of the embryologic timing of the genetic event locally, which leads to café-au-lait type hyperpigmentation. Because the facial features and the ectoderm overlying the facial muscles develop around the third to fourth week of gestation, the distribution of this café-au-lait macule suggests development at the same time.

Bilateral segmental neurofibromatosis: a case report and review

Bilateral segmental neurofibromatosis is a rare condition characterized by the occurrence of neurofibromas and/or café-au-lait spots limited to an area or segment of the body bilaterally. It is caused by a postzygotic mutation in the neurofibromatosis type I gene, resulting in a phenotype of genetic mosaicism. This report describes a case of bilateral segmental neurofibromatosis with multiple nodules sitting on a café-au-lait spot.