Resham Ejaz

Lateral meningocele (Lehman) syndrome: A child with a novel NOTCH3 mutation.

Lateral meningocele syndrome (LMS), or Lehman syndrome, is a rare disorder characterized by multiple lateral spinal meningoceles, distinctive facial features, joint hypermobility and hypotonia, along with skeletal, cardiac, and urogenital anomalies. Heterozygous NOTCH3 mutations affecting the terminal exon 33 were recently reported as causative in six families with LMS. We report a boy with LMS, the fourteenth reported case, with a de novo 80 base pair deletion in exon 33 of NOTCH3. Our patients prenatal findings, complex cardiac anomalies, and severe feeding difficulties further expand our understanding of this rare condition.

The evolving features of Nicolaides–Baraitser syndrome – a clinical report of a 20‐year follow‐up

Nicolaides–Baraitser syndrome (NCBRS) is a rare genetic condition associated with SMARCA2 gene mutations. Clinical diagnosis is challenging as its features evolve with time. The 20 years follow‐up of our NCBRS patient, with a previously unreported SMARCA2 mutation, illustrates the syndromes natural history and its clinical variability, especially in a milder form.

Primary mediastinal paraganglioma associated with a familial variant in the succinate dehydrogenase B subunit gene

Surgical management is the mainstay of therapy for primary cardiac tumors, yet due to the rarity of these malignancies, their management and workup remains a challenge. Here, we report a unique case of a patient with a primary left ventricular cardiac paraganglioma (PGL) and describe the role of a medical genetics assessment leading to the identification of a rare variant in the SDHB gene to be the causative etiology of this cardiac tumor. Due to decreasing costs and accessibility of molecular genetic analysis, genetic testing may become an emerging diagnostic adjunct in cases of cardiac tumors.

De novo pathogenic variant in TUBB2A presenting with arthrogryposis multiplex congenita, brain abnormalities, and severe developmental delay

Disorders of brain formation can occur from pathogenic variants in various alpha and beta tubulin genes. Heterozygous pathogenic variants in the beta tubulin isotype A gene, TUBB2A, have been recently implicated in brain malformations, seizures, and developmental delay. Limited information is known regarding the phenotypic spectrum associated with pathogenic variants in this gene given the rarity of the condition. We report the sixth individual with a de novo heterozygous TUBB2A pathogenic variant, who presented with a severe neurological phenotype along with unique features of arthrogryposis multiplex congenita, optic nerve hypoplasia, dysmorphic facial features, and vocal cord paralysis, thereby expanding the gene‐related phenotype.

Stable transmission of an unbalanced chromosome 21 derived from chromoanasynthesis in a patient with a SYNGAP1 likely pathogenic variant

BackgroundComplex genomic structural variations, involving chromoanagenesis, have been implicated in multiple congenital anomalies and abnormal neurodevelopment. Familial inheritance of complex chromosomal structural alteration resulting from germline chromoanagenesis-type mechanisms are limited.Case presentationWe report a two-year eleven-month old male presenting with epilepsy, ataxia and dysmorphic features of unknown etiology. Chromosomal microarray identified a complex unbalanced rearrangement involving chromosome 21. G-banding and FISH for targeted regions of chromosome 21 revealed that the copy number imbalances were limited to gains dispersed throughout the long arm of chromosome 21, characteristic of a chromosome derived from chromoanagenesis. Family studies showed that the unbalanced chromosome had been stably inherited, as it was present in both his healthy mother and maternal grandfather. Further molecular testing for non-syndromic intellectual disability genes found a likely pathogenic mutation in SYNGAP1 (NM_006772.2:c.3722_3723del).ConclusionsThis study indicates that complex rearrangements involving an unbalanced chromosome derived from chromoanasynthesis can be familial and should be not be presumed pathogenic.

Impact of Mobility Device Use on Quality of Life in Children With Friedreich Ataxia

Objective: To determine how mobility device use impacts quality of life in children with Friedreich ataxia. Study Design: Data from 111 pediatric patients with genetically confirmed Friedreich ataxia were collected from a prospective natural history study utilizing standardized clinical evaluations, including health-related quality of life using the Pediatric Quality of Life Inventory (PedsQL) 4.0 Generic Core Module. Results: Mobility device use was associated with worse mean PedsQL total, physical, emotional, social, and academic subscores, after adjusting for gender, age of disease onset, and Friedreich Ataxia Rating Scale score. The magnitude of the difference was greatest for the physical subscore (–19.5 points, 95% CI = –30.00, –8.99, P < .001) and least for the emotional subscore (–10.61 points, 95% CI = –20.21, –1.02, P = .03). Transition to or between mobility devices trended toward worse physical subscore (–16.20 points, 95% CI = –32.07, –0.33, P = .05). Conclusions: Mobility device use is associated with significant worsening of all domains of quality of life in children with Friedreich ataxia.

Riboflavin transporter deficiency mimicking mitochondrial myopathy caused by complex II deficiency

Biallelic likely pathogenic variants in SLC52A2 and SLC52A3 cause riboflavin transporter deficiency. It is characterized by muscle weakness, ataxia, progressive ponto‐bulbar palsy, amyotrophy, and sensorineural hearing loss. Oral riboflavin halts disease progression and may reverse symptoms. We report two new patients whose clinical and biochemical features were mimicking mitochondrial myopathy. Patient 1 is an 8‐year‐old male with global developmental delay, axial and appendicular hypotonia, ataxia, and sensorineural hearing loss. His muscle biopsy showed complex II deficiency and ragged red fibers consistent with mitochondrial myopathy. Whole exome sequencing revealed a homozygous likely pathogenic variant in SLC52A2 (c.917G>A; p.Gly306Glu). Patient 2 is a 14‐month‐old boy with global developmental delay, respiratory insufficiency requiring ventilator support within the first year of life. His muscle biopsy revealed combined complex II + III deficiency and ragged red fibers consistent with mitochondrial myopathy. Whole exome sequencing identified a homozygous likely pathogenic variant in SCL52A3 (c.1223G>A; p.Gly408Asp). We report two new patients with riboflavin transporter deficiency, caused by mutations in two different riboflavin transporter genes. Both patients presented with complex II deficiency. This treatable neurometabolic disorder can mimic mitochondrial myopathy. In patients with complex II deficiency, riboflavin transporter deficiency should be included in the differential diagnosis to allow early treatment and improve neurodevelopmental outcome.