Giant Cell Aortitis and Noonan Syndrome

Rare Metabolic and Endocrine Diseases with Cardiovascular Involvement: Insights from Cardiovascular Magnetic Resonance - A Review

The identification of rare diseases with cardiovascular involvement poses significant diagnostic challenges due to the rarity of the diseases, but also due to the lack of knowledge and expertise. Most of them remain underrecognized and undiagnosed, leading to clinical mismanagement and affecting the patients' prognosis, as these diseases are per definition life-threatening or chronic debilitating. This article reviews the cardiovascular involvement of the most well-known rare metabolic and endocrine diseases and their diagnostic approach through the lens of cardiovascular magnetic resonance (CMR) imaging and its prognostic role, highlighting its fundamental value compared to other imaging modalities.

Association between pectus excavatum and congenital genetic disorders: A systematic review and practical guide for the treating physician

BACKGROUND

Pectus excavatum (PE) could be part of a genetic disorder, which then has implications regarding comorbidity, the surgical correction of PE, and reproductive choices. However, referral of a patient presenting with PE for genetic analysis is often delayed because additional crucial clinical signs may be subtle or even missed in syndromic patients. We reviewed the literature to inventory known genetic disorders associated with PE and create a standardized protocol for clinical evaluation.

METHODS

A systematic literature search was performed in electronic databases. Genetic disorders were considered associated with PE if studies reported at least five cases with PE. Characteristics of each genetic disorder were extracted from the literature and the OMIM database in order to create a practical guide for the clinician.

RESULTS

After removal of duplicates from the initial search, 1632 citations remained. Eventually, we included 119 full text articles, representing 20 different genetic disorders. Relevant characteristics and important clinical signs of each genetic disorder were summarized providing a standardized protocol in the form of a scoring list. The most important clinical sign was a positive family history for PE and/or congenital heart defect.

CONCLUSIONS

Twenty unique genetic disorders have been found associated with PE. We have created a scoring list for the clinician that systematically evaluates crucial clinical signs, thereby facilitating decision making for referral to a clinical geneticist.

Cardiovascular disease in Noonan syndrome

PURPOSE OF REVIEW

To provide information on the scope of cardiac disease in Noonan syndrome.

RECENT FINDINGS

Noonan syndrome is a common autosomal dominant RASopathy disorder characterized by clinical findings of facial dysmorphism, congenital heart disease, and short stature. The degree of genetic heterogeneity has recently become evident in that Noonan syndrome is now known to be caused by mutations in a large variety of genes which produce dysregulation of the RAS-MAPK (mitogen-activated protein kinase) signaling pathway. The scope of cardiac disease in Noonan syndrome is quite variable depending on the gene mutation, with some mutations usually associated with a high incidence of congenital heart defects (PTPN11, KRAS, and others) while those with predominantly hypertrophic cardiomyopathy (HCM) have higher risk and morbidity profiles (RAF1, RIT1, and those associated with multiple lentigines).

SUMMARY

Cardiac disease in Noonan syndrome varies according to the type of gene mutation. The most common forms of cardiac disease include pulmonary stenosis, HCM, and atrial septal defect. HCM in general is associated with increased risk, mortality, and morbidity. New concepts for potential treatments are discussed.

Frequency of aortic dilation in Noonan syndrome

Noonan syndrome (NS) is a genetic disorder caused by mutations altering proteins relevant to RAS/mitogen-activated protein kinase signal transduction. Cardiac involvement is common, most prevalently pulmonary valve stenosis and hypertrophic cardiomyopathy. Because abnormal mitogen-activated protein kinase signaling contributes to the aortopathy in Marfan syndrome and with rare reports of aortic aneurysm in NS, we undertook a retrospective study of ascending aortic anatomy in 37 patients with NS and without confounding medical conditions. Age ranged from 0.6 to 32 years. Based on the most recent echocardiogram, the aortic annulus and root were dilated in the cohort (mean z scores of 1.14 and 0.98, respectively, p <0.005) but the sinotubular junction and ascending aorta were not (mean z scores of 0.05 and 0.19, respectively). The aortic root was aneurysmal (>2 z scores) in 8 subjects (21.6%). PTPN11 mutations were present in 14 subjects, whose aortic status was similar to the cohort overall. Comparison of age and z scores revealed a modest tendency for the aortic annulus and root to dilate over time. Among 13 subjects with multiple imaging studies over an average of 6.8 years, the average z score increased to 0.78 and 0.39 for the aortic annulus and root, respectively. Multivariate analysis revealed that age accounted for 7.0% and 11.0% of the variance in the aortic annular and root diameters, respectively. In conclusion, we found that aortic annular dilation and aortic root aneurysm are prevalent in NS, often presenting during childhood and progressing over time. Further study is needed to identify potential risks associated with these abnormalities.