Corino de Andrade disease: mechanisms and impact on reproduction

Preimplantation genetic testing for familial amyloid polyneuropathy

Background

Embryo selection in Familial amyloid polyneuropathy eradicates the disease, but the widespread application of preimplantation genetic testing (PGT) for this monogenic disease still requires greater political and clinical commitment.

Main body

Familial amyloid polyneuropathy is a fatal, chronic, hereditary autosomal dominant neurodegenerative disorder caused by a single nucleotide mutation in the transthyretin gene. The disease courses with infertility, cachexia, blindness, renal failure, cardiovascular collapse, and premature death. Treatments include organ transplantation, transthyretin stabilizers, silencers and gene editing. Unfortunately, these treatments only improve the patient’s quality of life.

Short conclusion

The application of PGT would prevent the disease, the birth of children with this devastating disease and the enormous health costs associated. For PGT to become the first reproductive option for patients, a paradigm shift in governmental, social and medical policies is necessary.

Protein Aggregation and Self Assembly in Health and Disease

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Self-attachment of proteins leading to the formation of highly insoluble protein oligomers and aggregates has become an important focus of research owing to its diverse implications in pathophysiology and diseases. This has become a more frequent phenomenon in most neurological and neurodegenerative diseases as well as in dementia. In recent years such event of protein aggregation has linked to other disease conditions, disorders or adverse health conditions. Interestingly, aggregation of protein also plays role in development, growth or metabolism. Most often physiological proteins are initially bio-synthesised in native or nascent geometrical forms or conformations but later they undergo specific folding pattern and thereby acquire a stable configuration that is biologically relevant and active. It is highly important that these proteins remain in their biologically active configuration in order to exert their functional properties. Any alteration or change to this structural configuration can be detrimental to their specific functions and may cause pathological consequences leading to the onset of diseases or disorders. Several factors such as the action of chaperones, binding partners, physiological metal ions, pH level, temperature, ionic strength, interfacial exposure (solid-liquid, liquid-liquid, gas-liquid), mutation and post translational modification, chemical changes, interaction with small molecules such as lipids, hormones, etc. and solvent environment have been either identified or proposed as important factors in conferring the ultimate status of protein structure and configuration. Among many misfolding protein conformations, self-assembly or aggregation is the most significant. It leads to the formation of highly oligomeric self-aggregates that precipitate and interfere with many biochemical processes with serious pathological consequences. The most common implication of protein aggregation leading to the formation of deposits / plaques of various morphological types is the onset of neurological and neurodegenerative diseases that include Alzheimer’s, Parkinson’s, Huntington, ALS (Amyotrophic Lateral Sclerosis), CJD (Creutzfeldt Jakob Dementia), Prion diseases, Amyloidosis and other forms of dementia. However increasingly studies revealed that protein aggregation may also be associated with other diseases such as cancer, type 2 diabetes, renal, corneal and cardiovascular diseases. Protein aggregation diseases are now considered as part of “Proteinopathy” which refers to conditions where proteins become structurally abnormal or fail to fold into stable normal configurations. In this review, we reflect on various aspects of protein self-aggregation, potential underlying causes, mechanism, role of secondary structures, pathological consequences and possible intervention strategies as reported in published literatures.

Diagnosis and treatment of urinary and sexual dysfunction in hereditary TTR amyloidosis

Purpose

We aimed to review the current knowledge on the epidemiology, diagnosis, and management of urinary and sexual dysfunction in patients with TTR amyloidosis (ATTR).

Methods

We performed a review of the literature, screening for randomized controlled trials, prospective and retrospective series, position papers, and guidelines on urinary and sexual dysfunction in ATTR patients published in PubMed and Embase.

Results

Lower urinary tract dysfunction is present in up to 83% of patients with ATTR. Voiding symptoms are the most common, reported in 34.8−87.5% of patients, while urinary tract infections are reported in up to 50%. Urinary incontinence is observed in 16.7−37.5% of the ATTR population, mostly due to decreased urethral resistance. Sexual dysfunction affects over 40% of ATTR patients, with erectile dysfunction and sexual arousal disorder being the most common symptoms in male and female patients, respectively. In addition to a thorough clinical examination, invasive pressure-flow urodynamic testing is a cornerstone in the assessment of ATTR lower urinary tract dysfunction. The most common finding is detrusor underactivity and intrinsic sphincter deficiency. Poor bladder compliance can also be observed in patients, due to amyloid deposits on the bladder wall. Urinary tract imaging may be of interest to rule out upper urinary tract deterioration. Given the paucity of data in the ATTR population, treatment should be tailored to the individual patient.

Conclusion

Urinary and sexual dysfunction are highly prevalent in ATTR patients. Comprehensive assessment and multidisciplinary management are keys to avoiding upper urinary tract damage and improving patients’ quality of life.