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Genetic Counseling in Assisted Reproductive Technology
Published in Carlos Simón, Carmen Rubio, Handbook of Genetic Diagnostic Technologies in Reproductive Medicine, 2022
Autosomal dominant inheritance is when mutation in one allele of an autosomal gene is sufficient to cause disease. An affected individual typically has one non-functional allele and one functional allele. Either allele can be passed on to subsequent generations, resulting in a 50% recurrence risk for each offspring. Dominant conditions can sometimes be seen in a family, passed down from generation to generation and shared among siblings. Sometimes, dominant conditions are caused by a de novo gene change, when an individual can be the first in the family to be affected.
Paper 1
Published in Aalia Khan, Ramsey Jabbour, Almas Rehman, nMRCGP Applied Knowledge Test Study Guide, 2021
Aalia Khan, Ramsey Jabbour, Almas Rehman
Marfan’s syndrome is an example of autosomal dominant inheritance. Other examples include Huntingdon’s disease, adult polycystic kidney disease and neurofibromatosis type 1. Cystic fibrosis, Tay-Sach’s and sickle-cell disease are recessive conditions.
Paper 2
Published in Amanda Rabone, Benedict Thomson, Nicky Dineen, Vincent Helyar, Aidan Shaw, The Final FRCR, 2020
Amanda Rabone, Benedict Thomson, Nicky Dineen, Vincent Helyar, Aidan Shaw
The patient has a condition with an autosomal dominant inheritance pattern. There are several polyposis syndromes; however, the one associated with cervical adenoma malignum is Peutz-Jeghers syndrome. Multiple gastrointestinal polyps can lead to presentations for haemorrhage and bowel obstruction secondary to intussusception. Patients also frequently have oral mucocutaneous pigmentation which can also affect the fingers and toes.
Histopathology of the Conduction System in Long QT Syndrome
Published in Fetal and Pediatric Pathology, 2022
Alexandra Rogers, Rachel Taylor, Janet Poulik, Bahig M. Shehata
There has also been evidence suggesting that JLNS could be inherited in an autosomal dominant fashion. This was demonstrated by Sanyal et al., who spent 16 years tracking the inheritance of JLNS in a family of 66 blood relatives. Results demonstrated that in families where one parent was diagnosed with JLNS, nearly 70% of offspring were also affected. Comparatively, in families where neither parent was afflicted, 0% of offspring had JLNS [7]. The significantly increased rate of successive generational affliction suggests an autosomal dominant inheritance. These findings were corroborated by Splawski et al. who postulated an autosomal dominant mode of inheritance for JLNS with an autosomal recessive inheritance pattern for the associated sensorineural deafness [7]. Several other studies have also confirmed these data, however, no final consensus has been reached regarding the mode of inheritance of JLNS.
A special case of hypertrophic cardiomyopathy with a differential diagnosis of isolated cardiac amyloidosis or junctophilin type 2 associated cardiomyopathy
Published in Acta Clinica Belgica, 2021
Sévérine De Bruijn, Xavier Galloo, Gilles De Keulenaer, Edgard A. Prihadi, Christiane Brands, Mark Helbert
In ATTR, the hepatic transport protein TTR, previously called prealbumin, is misfolded into an amyloid protein. TTR-related CA accounts for 18% of all cases of CA and is characterised by a progressive infiltrative cardiomyopathy that mimics hypertensive hypertrophic heart disease [7]. Transthyretin amyloidosis encompasses two subtypes. The hereditary/familial type (mATTR) – also called mutant type – arises from misfolding a mutated TTR precursor protein. It is characterized by autosomal dominant inheritance with variable penetrance. In sporadic or wild type (wtATTR), formally also known as senile systemic amyloidosis (SSA), amyloid arises from genetically unaltered TTR [9]. In contrast to AL amyloidosis, mATTR and wtATTR are typically associated with milder clinical manifestations, slower progression, and hence also better prognosis. Since the very slow progression (an 86-your-old patient) and mild clinical presentation (general fatigue with only mild decreased systolic function and no overt clinical heart decompensation) the differential diagnosis of an AL amyloidosis is very improbable based on anamnesis and physical exam. Further work-up confirmed normal immunoglobulin light chains. Arguments in favour of an ATTR are elderly patient, male, slow progression and mild clinical symptoms. As the patient described above only presents cardiac manifestations without altered kidney or liver function, the preferred differential diagnosis of wtATTR is withheld over mATTR.
Iron overload directly affecting the ovaries in a patient with Diamond–Blackfan anaemia: a case report
Published in Human Fertility, 2018
Mariano Mascarenhas, Victoria Rawnsley, Adam Balen
The overall incidence of DBA appears to be between 1/100,000 and 1/200,000 and is uniform across ethnicities and both sexes are equally likely to be affected. DBA has a complex inheritance pattern and in most cases, one altered gene appears to be sufficient to cause the condition. Around 40–45% of cases are familial with an autosomal dominant inheritance. The remainder are thought to be either familial with other patterns of inheritance or sporadic due to de-novo mutations. There is significant clinical heterogeneity with reduced penetrance and variable clinical manifestations even between family members carrying the same mutation (Vlachos et al., 2008). Genetic mutations affecting ribosomal protein synthesis are thought to underlie DBA. The most common mutation involves RPS19 gene which encodes a protein associated with the 40S subunit of the ribosome. Up to 113 different RPS19 mutations have been found to be associated with DBA (Lipton, 2007). However, the underlying mutations in a significant proportion of patients with DBA remain unidentified. Our patient had underwent genetic testing for the common variants causing DBA, but this was negative and the genetic material had been stored for further testing pending the discovery of new markers. Since there was no family history and this was a sporadic/de-novo mutation, linkage analysis could not be performed.