Case 34-2016. A 17-Year-Old Boy with Myopia and Craniofacial and Skeletal Abnormalities

Epigenetic memory: gene writer, eraser and homocysteine

Naturally chromatin remodeling is highly organized, consisting of histone acetylation (opening/relaxation of the compact chromatin structure), DNA methylation (inhibition of the gene expression activity) and sequence rearrangement by shifting. All this is essentially required for proper "in-printing and off-printing" of genes thus ensuring the epigenetic memory process. Any imbalance in ratios of DNA methyltransferase (DNMT, gene writer), fat-mass obesity-associated protein (FTO, gene eraser) and product (function) homocysteine (Hcy) could lead to numerous diseases. Interestingly, a similar process also happens in stem cells during embryogenesis and development. Despite gigantic unsuccessful efforts undertaken thus far toward the conversion of a stem cell into a functional cardiomyocyte, there has been hardly any study that shows successful conversion of a stem cell into a multinucleated cardiomyocyte. We have shown nuclear hypertrophy during heart failure, however; the mechanism(s) of epigenetic memory, regulation of genes during fertilization, embryogenesis, development and during adulthood remain far from understanding. In addition, there may be a connection of aging, loosing of the memory leading to death, and presumably to reincarnation. This review highlights some of these pertinent issues facing the discipline of biology as a whole today.

The Genetics of Pneumothorax

A genetic influence on spontaneous pneumothoraces-those occurring without a traumatic or iatrogenic cause-is supported by several lines of evidence: 1) pneumothorax can cluster in families (i.e., familial spontaneous pneumothorax), 2) mutations in the FLCN gene have been found in both familial and sporadic cases, and 3) pneumothorax is a known complication of several genetic syndromes. Herein, we review known genetic contributions to both sporadic and familial pneumothorax. We summarize the pneumothorax-associated genetic syndromes, including Birt-Hogg-Dubé syndrome, Marfan syndrome, vascular (type IV) Ehlers-Danlos syndrome, alpha-1 antitrypsin deficiency, tuberous sclerosis complex/lymphangioleiomyomatosis, Loeys-Dietz syndrome, cystic fibrosis, homocystinuria, and cutis laxa, among others. At times, pneumothorax is their herald manifestation. These syndromes have serious potential extrapulmonary complications (e.g., malignant renal tumors in Birt-Hogg-Dubé syndrome), and surveillance and/or treatment is available for most disorders; thus, establishing a diagnosis is critical. To facilitate this, we provide an algorithm to guide the clinician in discerning which cases of spontaneous pneumothorax may have a genetic or familial contribution, which cases warrant genetic testing, and which cases should prompt an evaluation by a geneticist.

Spinal cord injury following a mild trauma in homocystinuria-related bone frailty: neurorehabilitation and education on bone health management

Homocystinuria (HCU) is a rare autosomal recessive disease characterized by the deficiency of cystathionine β-synthetase, presenting with variable clinical features including micronutrient deficiency-related osteoporosis. Early-onset osteoporosis results in increased bone fragility, which is associated with low-impact fractures. To date, no traumatic myelopathy has ever been described in patients with HCU. This case report describes a 30-year-old male patient with HCU who was not aware that he was at high risk of sustaining debilitating bone fractures. After a mild trauma, he reported a T12 compression fracture with spinal cord injury. The patient underwent a tailored rehabilitation program, on the basis of multidisciplinary approach, and was educated about the increased risk of fractures, maintaining adherence to treatment and diet, having an active lifestyle, avoiding excessive weight loss, and preventing falls or other traumatic injury. To reduce the risk of fractures - with possible catastrophic consequences - patients with HCU, and their caregivers, should be educated about prevention of fractures.