Congenital glaucoma and neurofibromatosis in a monozygotic twin: case report and review of the literature

Diagnosis of neonatal neurofibromatosis type 1: a case report and review of the literature

BACKGROUND

Neurofibromatosis Type 1 (NF1) is a rare genetic disorder characterized with the development of multiple benign tumors on the nerves and skin.

CASE PRESENTATION

This report described a neonatal case with a large mass observed on the left side of the maxillofacial and cervical region at birth. Meantime, multiple cafe-au-lait macules (CALMs) were seen on the trunk and both lower extremities.

CONCLUSIONS

In this case, the clinical features of the rare NF1 neonate are discussed along with its ultrasound findings.

Failure of XEN Gel Stent Implantation as a Stand-Alone Procedure in Congenital Glaucoma: Case Report of Secondary Congenital Glaucoma in Neurofibromatosis Type 1

A XEN gel stent implant procedure was performed in a one-year-old child with severe unilateral congenital glaucoma. At the age of 6 weeks, an uncomplicated 360° trabeculotomy had been performed, which resulted in intraocular pressure (IOP) control for only 4 months. The gel stent implantation was performed ab interno without complications. However, 1 month later, the stent was repelled into the anterior chamber due to the elasticity of Tenon's layer. A first revision surgery was performed, with excision of Tenon's layer and implantation of a new gel stent under sight. At the age of 18 months, a second revision surgery was performed because of an encapsulated Tenon cyst with insufficient IOP control, again with the implantation of a new stent. At that time, a progressive upper eyelid swelling was apparent. Eyelid biopsy led to the diagnosis of neurofibromatosis type 1, presenting with an orbital plexiform neurofibroma. Further insufficient IOP control resulted in a cyclodestructive procedure and loss of light perception during follow-up. XEN gel stent implantation in congenital glaucoma in infants is more challenging than that in adult patients. Gel stent implantation ab interno may be difficult due to the thickness and elasticity of Tenon's layer. Gel stent dislocation may occur, even months after surgery. Trabeculectomy might be a better approach after failed trabeculotomy in congenital glaucoma. An underlying systemic disease might become apparent late during follow-up.

Role, function and challenges of multidisciplinary centres for rare diseases exemplified for neurofibromatosis type 1 syndrome

PURPOSE

Neurofibromatosis type 1 (NF1) syndrome is a common rare/orphan disease that manifests itself early in the paediatric age. It imposes a considerable burden upon patients as well as on caregivers. Decisions regarding optimal care often rely on several medical instances working together as a team.

METHODS

The authors reviewed the literature and supplied a description of their own clinical work at the NF1 centres.

RESULTS

The experience of a multidisciplinary teamwork of three NF centres was summarized in order to enhance awareness for possible multidisciplinary ways of delivery of health and health-related aspects of care to NF1 patients. Both population-focused research centres and family-focused centres were reviewed.

CONCLUSIONS

Chronic rare diseases that start in the paediatric age mandate long-term follow-up most often by several disciplines. NF1 syndrome is an example of a multidisciplinary centre in order to enhance the quality of care.

Analysis of copy number variants in 11 pairs of monozygotic twins with neurofibromatosis type 1

Phenotypic variability among individuals with neurofibromatosis type 1 (NF1) has long been a challenge for clinicians and an enigma for researchers. Members of the same family and even identical twins with NF1 often demonstrate variable disease expression. Many mechanisms for this variability have been proposed. We have performed an exploratory study of copy number variants (CNVs) as a possible source of phenotypic variability in NF1. We enrolled 11 pairs of monozygotic (MZ) twins with NF1 and their parents, catalogued their clinical characteristics, and utilized a single nucleotide polymorphism (SNP) microarray to identify CNVs in blood and saliva. The 11 twin pairs showed high concordance for presence and number of café-au-lait spots, cutaneous neurofibromas, IQ, and ADHD. They were more likely to be discordant for optic pathway glioma, plexiform neurofibromas, skeletal manifestations, and malignancy. Microarray analysis identified a total of 81 CNVs meeting our conservative criteria, 37 of which overlap known genes. Of interest, three CNVs were previously unreported. Microarray analysis failed to ascertain any CNV differences within twin pairs, between twins and parents, or between tissues in any one individual. Results of this small pilot study did not demonstrate any de novo CNV events in our MZ twin pairs, nor were de novo CNVs overrepresented in these individuals with NF1. A much larger sample size would be needed to form any conclusions about the role of CNVs in NF1 variable expressivity. Alternative explanations for discordant phenotypes include epigenetic changes, smaller genetic alterations, or environmental factors. © 2016 Wiley Periodicals, Inc.

Childhood orbitotemporal neurofibromatosis masked by congenital glaucoma and buphthalmos

In newborns with unilateral buphthalmos and presumed congenital glaucoma, the differential diagnosis should include the rare condition of orbitotemporal neurofibromatosis. The authors present the diagnostic challenge of an unusual case of neurofibromatosis type 1 with unilateral congenital glaucoma, buphthalmos, and sphenoid-orbital dysplasia. The accompanying type of osseous orbital dysplasia has rarely been described in the literature, complicating the diagnostic and management process.

Variable expression of neurofibromatosis 1 in monozygotic twins

Neurofibromatosis 1 (NF1) is a common autosomal dominant disorder with high penetrance but extreme variability of expression. Monozygotic (MZ) twins with NF1 who have phenotypic discordances are a useful tool in evaluating which traits are influenced by non-hereditary influences such as second hit somatic events, environmental agents, epigenetic modification, or post-zygotic mutations. We evaluated nine sets of MZ twins and one set of MZ triplets, ages 4-18 years, for NF1 features and calculated probandwise concordance (P(C)) for each feature. MZ twins were highly concordant in numbers of café-au-lait spots (P(C) = 0.89) and cutaneous neurofibromas. IQ scores were within 10 points for all twin pairs tested, and similar patterns of learning disabilities and speech disorders were observed. Twin pairs showed significant discordance for tumors, particularly plexiform neurofibromas (P(C) = 0.40) and malignant peripheral nerves sheath tumors (MPNST), as expected if post-natal second-hit events were contributing to these features. One set of twins was concordant for multiple, large paraspinal neurofibromas, suggesting that there may be more hereditary factors involved in production of paraspinal neurofibromas. Four sets were concordant for pectus deformities of the chest (P(C) = 0.80). Three sets of twins were discordant for scoliosis (P(C) = 0.40); an additional set was concordant for scoliosis but differed in presence of dystrophic features and need for surgery. Our data suggest there are additional non-hereditary factors modifying the NF1 phenotype and causing discordancies between MZ twins. Future studies may focus on differences in epigenetic changes or somatic mosaicism which have been documented for other disease genes in MZ twins.

Unusual association of peripheral retinal ischemia-induced neovascular glaucoma and neurofibromatosis type 1

A 12-year-old girl with neurofibromatosis type 1 was referred for pain and blurred vision in her right eye for the past 2 weeks. Neovascular glaucoma associated with peripheral retinal ischemia was diagnosed and she was treated with retinal photocoagulation after intravitreal bevacizumab injection and trabeculectomy.

Management of congenital glaucoma in neurofibromatosis type 1: a report of two cases

The most frequent ophthalmic lesions associated to neurofibromatosis type 1 include iris Lisch nodules, optic nerve gliomas, and neurofibromas located on the eyelid, conjunctiva or orbit. Glaucoma is much less frequent, and it may be difficult to diagnose and treat. We present two patients with neurofibromatosis type 1 and associated congenital glaucoma. In case 1, the glaucoma was present at birth, and was the first symptom of the disease. It was surgically treated by means of an Ahmed glaucoma valve implantation, with good intraocular pressure (IOP) control after 13 months of follow-up. In case 2, the glaucoma appeared at 5 months old, and a trabeculectomy was initially performed; it failed 2 years later and an Ahmed glaucoma valve was then implanted, with adequate IOP control after 7 years of follow-up. Both children were males, and in both cases there were orbital neurofibromas and a dysplasia of the greater wing of the sphenoid of the same side. In case 2, orbital enlargement surgery was also performed at 4 years old. Congenital glaucoma management in the context of neurofibromatosis is very complex due to the frequent association of orbital and eyelid tumors and bone dysplasia, and its prognosis is usually poor. We present two cases in which good control of IOP has been achieved with Ahmed glaucoma valve implantation after 13 months and 7 years of follow-up.

[Congenital glaucoma and trabeculodysgenesis. Clinical and genetic aspects]

Congenital glaucoma is generally related to an iridocorneal angle malformation, with an obstacle to aqueous humor outflow. This spectrum of diseases can involve the angle, the iris and the cornea. The diagnosis relies on characteristic signs and is confirmed by an examination under general anaesthesia and paraclinical examinations (especially echography). An early diagnosis is essential for beginning surgical treatment. Several filtering surgery techniques with equivalent intraocular pressure results are available, but visual function must be protected in all cases. In many cases, genetic counseling relies on a careful clinical analysis and sometimes on a molecular analysis. A number of ocular and/or general abnormalities can be accompanied by glaucoma in infants and children. They must be screened in case of associated signs, but the existence of these abnormalities leads to suspicion of associated glaucoma.

Non-random associations and vascular fields in neurofibromatosis 1: A pathogenetic hypothesis

Neurofibromatosis type 1 (NF1) is an autosomal dominant disorder with highly variable expression generally ascribed to random factors. However, evidence is presented for patterns suggesting non-stochastic processes as follows: (1) We have seen a MZ twin pair concordant for renal vascular hypertension, and another for unilateral ptosis. Other concordances have been reported, including both malformations and tumors, and combinations as well. (2) Four children were seen with a distinct ipsilateral association of glaucoma or iris anomaly, optic glioma, plexiform neurofibromas arising from the trigeminal nerve and its branches, and sphenoid dysplasia. Other cases in the literature support milder forms of this association. (3) We saw six children with apparent gynecomastia or premature thelarche without endocrine abnormalities. Tissue samples from four of these showed an unusual fibrous plexiform neurofibroma. Interestingly, five of the six cases were African Americans, and constitutional factors affecting fibrous reactions may also be involved here.A tentative hypothesis is presented suggesting vascular fields involving defined areas that can: (1) Support tumor growth. They would be the "soil" determining the ability and the extent of growth. There would, however, still be a need for a "second hit" tumor transformation. (2) Affect blood supply to organs, creating structural anomalies. NF1 involves a vasculopathy, and would predispose to vulnerabilities of such fields. Genetic factors could induce superimposed susceptibilities of specific fields, leading to twin concordances. "Hits" affecting specific fields would increase the likelihood of multiple abnormalities that could include both tumors and structural findings. Finally, tumors may follow the contours of existing fields. The breast is an area normally primed for growth, and the observation of clitoromegally secondary to tumor involvement suggests that such fields exist elsewhere.

Ophthalmological manifestations in VHL and NF 1: pathological and diagnostic implications

Von Hippel-Lindau disease (VHL) and neurofibromatosis type 1 (NF 1) are hereditary multitumor syndromes that show associated ocular manifestations. Capillary retinal angioma, a benign vascular tumor, is the classical ocular lesion in VHL. It often appears as the first manifestation of the disease and may thus lead to the diagnosis of VHL. Since small angiomas can be treated easily by laser photocoagulation, a regular ocular screening of VHL patients is recommended. Ocular manifestations of NF 1 are more diverse as compared to VHL. Lisch nodules of the iris are an important diagnostic criteria of NF 1 since they can be found in almost every affected patient. Optic glioma can occur both intraorbitally and intracranially. The intraorbital form causes progressive protrusion of the globe and eventually blindness. Extension of the tumor beyond the chiasm worsens the prognosis quoad vitam. The hallmark of NF 1, namely cutaneous neurofibroma can cause visual impairment when affecting the skin of the eyelids. The rare intraorbital pexiform neurofibroma is associated with abnormal development of the orbital bones and infantile glaucoma. It may result in orbital mass effects and therefore may need surgical excision.

Management of childhood glaucoma

PURPOSE OF REVIEW

Management of childhood glaucomas is a challenging responsibility. This review will highlight new information to assist with preparation for the care of patients with these disorders.

RECENT FINDINGS

During the past year, work was reported revealing new causes of childhood glaucoma and incredible new insight into the responsible genetic defects. This report also reviews continued efforts to determine the indications and outcomes of goniosurgery, trabeculectomy procedures, and tube shunts for children.

SUMMARY

Continued progress in understanding the genetics of childhood glaucoma and the selection of effective surgical procedures highlight progress reported in the last year and should assist with decision making for children with childhood glaucoma.