The first case of X-linked Alpha-thalassemia/mental retardation (ATR-X) syndrome in Korea

Genetics behind Cerebral Disease with Ocular Comorbidity: Finding Parallels between the Brain and Eye Molecular Pathology

Cerebral visual impairments (CVIs) is an umbrella term that categorizes miscellaneous visual defects with parallel genetic brain disorders. While the manifestations of CVIs are diverse and ambiguous, molecular diagnostics stand out as a powerful approach for understanding pathomechanisms in CVIs. Nevertheless, the characterization of CVI disease cohorts has been fragmented and lacks integration. By revisiting the genome-wide and phenome-wide association studies (GWAS and PheWAS), we clustered a handful of renowned CVIs into five ontology groups, namely ciliopathies (Joubert syndrome, Bardet–Biedl syndrome, Alstrom syndrome), demyelination diseases (multiple sclerosis, Alexander disease, Pelizaeus–Merzbacher disease), transcriptional deregulation diseases (Mowat–Wilson disease, Pitt–Hopkins disease, Rett syndrome, Cockayne syndrome, X-linked alpha-thalassaemia mental retardation), compromised peroxisome disorders (Zellweger spectrum disorder, Refsum disease), and channelopathies (neuromyelitis optica spectrum disorder), and reviewed several mutation hotspots currently found to be associated with the CVIs. Moreover, we discussed the common manifestations in the brain and the eye, and collated animal study findings to discuss plausible gene editing strategies for future CVI correction.

Epilepsy and Sleep in the ATR-X Syndrome

BACKGROUND

This study explores the prevalence, clinical characteristics, and treatment of epilepsy and sleep disorders in α thalassemia mental retardation (ATR-X) syndrome.

DESIGN

In this cross-sectional study, 37 participants with ATR-X syndrome aged 1.8 to 44 years were studied using a customized epilepsy questionnaire, review of electroencephalography (EEG) findings, the modified Sleep Questionnaire of Simonds and Parraga and 2-week sleep diary.

RESULTS

Eleven participants had a clinical diagnosis of generalized epilepsy (29.7%). Seizure types were generalized tonic-clonic seizures, absences, and myoclonia. Interictal EEG recordings in participants with GTCS showed no epileptic discharges in 78%. Similarly, EEG recordings during myoclonia and absences often demonstrated no epileptic discharges. Sleep problems (difficulty falling or maintaining sleep, and early awakening) were reported in 70%. Participants with reported sleep problems went to bed earlier (p = 0.027) and had a lower sleep efficiency (p < 0.01) than participants without sleep problems, but as a group they both had a sufficient total sleep time (9 hours and 52 minutes vs. 10 hours and 55 minutes). Sixteen participants (43.2) used medication to improve sleep (predominantly melatonin n = 10), being effective in only two.

CONCLUSION

One-third of participants with ATR-X syndrome had a clinical diagnosis of epilepsy, but the absence of EEG abnormalities in suspected epileptic seizures questions this diagnosis in these patients. EEG recording during seizure like symptoms is warranted before making an epilepsy diagnosis. Seventy percent experienced sleep problems, although total sleep time was normal in most participants. Long bedtimes might have a negative influence on sleep efficiency.

Perspectives in Pediatric Pathology, Chapter 6. Male Undermasculinization

Normal male development requires three conditions: (1) adequate differentiation of the fetal testis; (2) synthesis and secretion of testicular hormones; and (3) effective action of these hormones on target organs. This requires the combined action of the inhibitory anti-müllerian hormone (AMH, secreted by Sertoli cells) to block the development of the uterus and fallopian tubes from the müllerian duct, together with the trophic stimulus of testosterone (a Leydig cell product), which leads to virilization of the wolffian ducts. Additionally, the development of external genitalia depends on the conversion of testosterone to dihydrotestosterone by the enzyme 5-α-reductase. Failure of any of these mechanisms leads to deficient virilization or the so-called "male pseudohermaphroditism" syndromes.

Alpha-thalassemia X-linked intellectual disability syndrome identified by whole exome sequencing in two boys with white matter changes and developmental retardation

Alpha-thalassemia X-linked intellectual disability (ATRX) syndrome is a genetic syndrome caused by mutation of the ATRX gene associated with chromatin remodeling. Recently, a wide spectrum of brain MRI abnormalities and clinical manifestations has been recognized. We describe two male patients with genetically confirmed ATRX syndrome, both presented with developmental delay and white matter changes without typical clinical characteristics of ATRX. Whole-exome sequencing revealed the presence of ATRX mutations: a novel c.6472A>G mutation in Case 1 and a previously reported c.6532C>T mutation in Case 2. These two cases expanded the genetic and clinical spectrum of ATRX syndrome, including brain MRI abnormalities. Our results suggest that male patients with developmental delay and widespread white matter changes, even without distinctive facial dysmorphism and hematologic abnormalities, should be suspected as ATRX syndrome. We support the clinical utility of whole-exome sequencing, particularly in ultra-rare neurological diseases with nonspecific developmental disabilities and atypical presentation.