Faculty Bibliography

BACKGROUND:Binimetinib and selumetinib are two mitogen-activated protein kinase kinase (MEK) inhibitors used to treat low-grade gliomas and plexiform neurofibromas. Cutaneous toxicities are commonly associated with MEK inhibitors; however, limited studies have examined cutaneous effects in a pediatric population or whether toxicities vary between MEK inhibitors. METHODS:We conducted an IRB-approved, single-center, retrospective review of pediatric neuro-oncology patients on binimetinib or selumetinib who presented to NYU from April 2016 through July 2022. RESULTS:Forty-six children met inclusion criteria (23 females, 23 males) with a mean age of 11.7 years. Thirty-three were treated with binimetinib and 13 with selumetinib. Dermatologic adverse events were encountered in 97.8% of the cohort, and the most common were acneiform eruption (63.0%), paronychia (58.7%), and xerosis (54.3%). Children 12 years and older were more likely to have acneiform eruption (p < 0.001) and seborrheic dermatitis (p < 0.001), while children under 12 were more likely to have xerosis (p = 0.037). The incidence of cutaneous adverse events was significantly different between MEK inhibitors for folliculitis and hair pigment dilution (39.4% binimetinib, 0% selumetinib, p = 0.009). Significantly, more patients required MEK inhibitor dose reduction/hold on binimetinib (87.9%) than selumetinib (46.2%) (p = 0.006). Severity of cutaneous disease was not associated with tumor response. CONCLUSIONS:Our study confirms dermatologic adverse events are common in children on MEK inhibitors. Age appears to be associated with increased likelihood of certain cutaneous reactions. Overall, the selumetinib patients in our cohort presented with less severe adverse events and decreased risk of MEK inhibitor dose reduction/hold. Our results will aid clinicians in providing appropriate counseling, treatments, and improved preventive care.

Adult polyglucosan body disease (APBD) is a rare autosomal recessive glycogen storage disorder that leads to slowly progressive multi-organ dysfunction in adulthood. A novel disease-specific patient-reported outcome measure was created and administered to assess symptom burden and health-related quality of life (HR-QOL) in APBD. Thirty-six participants between 30 and 79 years of age (83% ≥60 years, 56% male) completed the anonymous questionnaire independently or with a caregiver proxy (75% self-report). Unemployment predicted an 18.3 (95% CI: 2.8, 33.8; p = 0.028) higher composite disease severity score and a 28.8 (95% CI: 8.2, 49.4; p = 0.010) higher composite HR-QOL score. Use of one or more assistive devices also predicted a 29.3 (95% CI: 8.3, 50.4; p = 0.011) higher composite disease severity score and a 41.8 (95% CI: 10.9, 72.8; p = 0.013) higher composite HR-QOL score. Proxy survey completion predicted a 19.4 (95% CI: 4.1, 34.7; p = 0.020) higher composite disease severity score compared to self-report. Older age at survey completion predicted a 27.4 higher composite HR-QOL score (95% CI: 2.5, 52.4; p = 0.039) for participants in their sixties compared to those between 30 and 59 years old. The development of the Adult Polyglucosan Body Disease questionnaire on Symptom burden and health-related Quality of life (APBD-SQ) marks an important stride forward in capturing the patient experience as a tool for disease monitoring and future research.

Cases of isolated spinal cord ischemia resulting in symptoms in neonates are rare, and there are even fewer reported cases in atraumatic births. We present a case of a presumed isolated cervical cord ischemic injury, discuss differentials to consider when evaluating a neonatal spinal cord injury, and highlight the difficulties of diagnosing a spinal cord infarction.

BACKGROUND:Adult polyglucosan body disease (APBD) is caused by a deficiency in glycogen branching enzyme that leads to polyglucosan accumulation in multiple organs. It has a progressive clinical course with prominent neurologic manifestations. We aim to describe the neuro-ophthalmic manifestations of APBD. METHODS:This is a case series of 3 individuals with genetically proven APBD. Written informed consent was provided by the brothers. We also performed a literature review on the current state of knowledge on APBD through PubMed. RESULTS:Brother 1 developed gait imbalance and length-dependent polyneuropathy in his 40s followed by progressive urinary symptoms in his 50s. He reported diplopia and blurry vision in his 60s. Neuro-ophthalmic assessment revealed bilateral optic neuropathy, convergence insufficiency, and a right fourth nerve palsy. Genetic testing showed a homozygous pathogenic variant in GBE1 c.986A>C p.Tyr329Ser. Brother 2 developed progressive urinary symptoms in his 40s that were followed by cognitive deficits, length-dependent polyneuropathy, and lower extremity weakness in his 50s and 60s. He reported blurred vision, and neuro-ophthalmic evaluation revealed bilateral optic neuropathy. Genetic testing revealed the same variant as Brother 1, GBE1 c.986A>C p.Tyr329Ser. Brother 3 developed progressive urinary urgency and lower extremity weakness in his 50s followed by a length-dependent polyneuropathy in his 60s. He reported diplopia and blurry vision in his 70s. Neuro-ophthalmic assessment revealed bilateral optic neuropathy and convergence insufficiency. Genetic testing revealed the same variant as Brothers 1 and 2, GBE1 c.986A>C p.Tyr329Ser. CONCLUSIONS:There is an array of afferent and efferent neuro-ophthalmic manifestations in APBD. Neuro-ophthalmic evaluation is crucial in evaluating and treating patients with APBD, particularly in those with visual dysfunction.

FEZF2 encodes a transcription factor critical to neurodevelopment that regulates other neurodevelopment genes. Rare variants in FEZF2 have previously been suggested to play a role in autism, and cases of 3p14 microdeletions that include FEZF2 share a neurodevelopmental phenotype including mild dysmorphic features and intellectual disability. We identified seven heterozygous predicted deleterious variants in FEZF2 (three frameshifts, one recurrent missense in two independent cases, one nonsense, and one complete gene deletion) in unrelated individuals with neurodevelopmental disorders including developmental delay/intellectual disability, autism, and/or attention-deficit/hyperactivity. Variants were confirmed to be de novo in five of seven cases and paternally inherited from an affected father in one. Predicted deleterious variants in FEZF2 may affect the expression of genes that are involved in fate choice pathways in developing neurons, and thus contribute to the neurodevelopmental phenotype. Future studies are needed to clarify the mechanism by which FEZF2 leads to this neurodevelopmental disorder.

BACKGROUND:Neurofibromatosis type 1 (NF1) is a multisystemic autosomal dominant disorder that includes intracranial lesions such as unidentified bright objects (UBOs)-areas of increased T2 signal on magnetic resonance imaging (MRI)-and tumors known as gliomas. The presence of these lesions in the corpus callosum (CC) has not been previously studied in a large cohort. METHODS:We reviewed medical records of 681 patients (aged three months to 86 years) followed at our institution from 2000 to 2023 with NF1 and one or more brain MRI. Patients with lesions in the CC were identified, and RAPNO/RANO criteria were used to determine changes in size over time, where a change of 25% in the product of perpendicular measurements indicates growth or shrinkage. RESULTS:Forty-seven patients had CC UBOs, most of which were in the splenium (66.0%). Seventeen patients had CC gliomas (10% of those with any glioma), two of whom had two gliomas. Seventeen of 19 gliomas were in the splenium. Over follow-up, eight of 19 remained stable, three shrunk, and eight grew. The mean percentage change in the product of the dimensions was 311.5% (ranging from -46.7% to 2566.6%). Of the eight lesions that grew, one required treatment. CONCLUSIONS:There is a 6.9% and 2.5% prevalence of CC UBOs and gliomas, respectively, in our cohort of patients with NF1. Most lesions are present in the splenium, and although some gliomas demonstrate significant growth, they rarely require treatment. This work is the largest series of CC lesions in NF1 and adds to the growing data to inform appropriate follow-up.

Congenital hydrocephalus (CH), characterized by cerebral ventriculomegaly, is one of the most common reasons for pediatric brain surgery. Recent studies have implicated lin-41 (lineage variant 41)/TRIM71 (tripartite motif 71) as a candidate CH risk gene, however, TRIM71 variants have not been systematically examined in a large patient cohort or conclusively linked with an OMIM syndrome. Through cross-sectional analysis of the largest assembled cohort of patients with cerebral ventriculomegaly, including neurosurgically-treated CH (totaling 2,697 parent-proband trios and 8,091 total exomes), we identified 13 protein-altering de novo variants (DNVs) in TRIM71 in unrelated children exhibiting variable ventriculomegaly, CH, developmental delay, dysmorphic features, and other structural brain defects including corpus callosum dysgenesis and white matter hypoplasia. Eight unrelated patients were found to harbor arginine variants, including two recurrent missense DNVs, at homologous positions in RPXGV motifs of different NHL domains. Seven additional patients with rare, damaging, unphased or transmitted variants of uncertain significance were also identified. NHL-domain variants of TRIM71 exhibited impaired binding to the canonical TRIM71 target CDKN1A; other variants failed to direct the subcellular localization of TRIM71 to processing bodies. Single-cell transcriptomic analysis of human embryos revealed expression of TRIM71 in early first-trimester neural stem cells of the brain. These data show TRIM71 is essential for human brain morphogenesis and that TRIM71 mutations cause a novel neurodevelopmental syndrome featuring ventriculomegaly and CH.