Özet

Baraitser-Winter syndrome is a very rare genetic disorder caused by cytoplasmic actin-encoding genes defects. Although most patients have similar phenotype, concomitant cardiac anomalies widely vary. In addition to well-described congenital heart diseases, aortic aneurysms occur due to underlying actin gene mutation in these patients in the further years. Herein, we present a 26-year-old male case who underwent Bentall procedure with the diagnosis of new-onset aortic valve regurgitation and an ascending aorta aneurysm.

Baraitser-Winter syndrome (BWS) is a very rare genetic disorder and was first described in 1988 in siblings as a combination of iris coloboma, bilateral ptosis, hypertelorism, broad nasal bridge, prominent epicanthic folds, and growth and mental retardation.[1] According to recent literature, BWS is caused by heterozygous missense mutations in ubiquitous cytoplasmic actin-encoding genes ACTB or ACTG1 which encode β- and γ-actins.[2]

Over years, several cases with similar resemblance of BWS have been reported worldwide, and the spectrum has been widened with microcornea, microphthalmia, microcephaly, trigonocephaly, gyral malformation, seizures, hypotonia, and cardiac, urogenital, and skeletal defects in addition to aforementioned dysmorphologies.[3-9] Although various congenital cardiac anomalies have been reported as clinical features of this syndrome including patent ductus arteriosus, ventricular septal defect, mitral-tricuspid valve prolapse, and mitraltricuspid regurgitation, BWS has no precise definition for adult patients.[5,6,9]

Herein, we describe a 26-year-old male case who underwent Bentall procedure with the diagnosis of new-onset aortic valve regurgitation and an ascending aorta aneurysm.

A 26-year-old male patient born from unrelated parents was diagnosed with BWS in 2001. The patient was referred to our center with a recent diagnosis of an ascending aortic aneurysm with severe aortic regurgitation. He was suffering from dyspnea and episodic chest pain. In his medical history, he was on medication with nebivolol 5 mg/day due to hypertension for three years and risperidone 1 mg per day ever since childhood. Previously, he underwent several operations due to other medical conditions such as umbilical hernia, dental diseases, pes planus, and scoliosis. In addition, he was on digoxin treatment from the neonatal period until the age of seven due to cardiomegaly and was under regular follow-up through transthoracic echocardiography (TTE) until three years ago (Figure 1).

Figure 1: Typical syndromic face features including short neck, broad nasal bridge, ptosis, hypertelorism, and epicanthic folds.

The physical examination findings were nonspecific, except 3/6 diastolic murmur. In addition, preoperative laboratory test results were normal. Computed tomography (CT) measured the enlargement in the ascending aorta as 6.7 cm, while the arcus and descending aorta were in normal width. Subsequent TTE indicated severe aortic regurgitation and left ventricular global hypokinesis with 50% ejection fraction. Mitral regurgitation was 1-2°. Therefore, the patient was scheduled for the Bentall procedure.

A written informed consent was obtained from the patient. As a cannulation strategy, aortic cannulation was planned through the left common femoral artery and a central two-stage cannula was planned for venous drainage. We accessed mediastinum via median sternotomy (Figure 2). Reaming surgical process was performed as usual. After the excision of the calcified aortic valve and dilated segment of the aorta, a 21 valve-sized composite Bentall graft was inserted. Coronary anastomoses were sutured as in standard Button-Bentall procedure. Total cardiopulmonary circulation time was 129 min and total cross-clamp time was 111 min. Following an uneventful postoperative course, he was extubated in the first day in the intensive care unit and was admitted to ward on the second day.

Figure 2: A view of dilated aortic segment and increased cardiac size.

Tartışma

To the best of our knowledge, the present case was the 14^th reported patient as of 2001 among the 42 reported patients worldwide until now.[10] Our patient"s physical appearance and clinical manifestations are consistent with significant phenotypic descriptions of BWS, such as short neck, broad nasal bridge, ptosis, hypertelorism, and epicanthic folds.

Henedy et al.[11] published a review in 2010 regarding the phenotypic spectrum of first 20 cases worldwide. According to the results, cardiac anomalies were observed in only six of them, and multiple anomalies were frequent in these cases. In the study of Ramer et al.[6] one case presented with a bicuspid aortic valve with mild aortic stenosis and a small patent ductus arteriosus and the other one presented with mitral valve prolapse, mitral regurgitation, tricuspid valve prolapse, and tricuspid regurgitation. Unfortunately, there is a lack of information about cardiac followup of such patients in the literature; therefore, we are unable to know how many of them needed surgical approach.

With the help of emerging technologies, as shown by many authors in different studies, defective actin proteins may cause aortic aneurysms and various cardiac diseases.[12-14] Baraitser-Winter syndrome is also one of them and aortic aneurysms may occur in these patients.

In conclusion, our case is uniquely the first reported adult patient with Baraitser-Winter syndrome who underwent cardiac surgery with the diagnosis of an aortic aneurysm and aortic regurgitation. We believe that these patients are under the risk of developing aortic and cardiac diseases and, therefore, should be kept in close echocardiographic follow-up.

Declaration of conflicting interests
The authors declared no conflicts of interest with respect to the authorship and/or publication of this article.

Funding
The authors received no financial support for the research and/or authorship of this article.

Kaynaklar

1) Baraitser M, Winter RM. Iris coloboma, ptosis, hypertelorism, and mental retardation: a new syndrome. J Med Genet 1988;25:41-3.

2) Rivière JB, van Bon BW, Hoischen A, Kholmanskikh SS, O'Roak BJ, Gilissen C, et al. De novo mutations in the actin genes ACTB and ACTG1 cause Baraitser-Winter syndrome. Nat Genet 2012;44:440-4.

3) Pallotta R. Iris coloboma, ptosis, hypertelorism, and mental retardation: a new syndrome possibly localised on chromosome 2. J Med Genet 1991;28:342-4.

4) Ramer JC, Mascari MJ, Manders E, Ladda RL. Syndrome identification #149: trigonocephaly, pachygyria, retinal coloboma, and cardiac defect: a distinct syndrome. Dysmorph Clic Genet 1992;6:15-20

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6) Ramer JC, Lin AE, Dobyns WB, Winter R, Aymé S, Pallotta R, et al. Previously apparently undescribed syndrome: shallow orbits, ptosis, coloboma, trigonocephaly, gyral malformations, and mental and growth retardation. Am J Med Genet 1995;57:403-9.

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9) Shiihara T, Maruyama K, Yamada Y, Nishimura A, Matsumoto N, Kato M, et al. A case of Baraitser-Winter syndrome with unusual brain MRI findings: pachygyria, subcortical-band heterotopia, and periventricular heterotopia. Brain Dev 2010;32:502-5.

10) Verloes A, Di Donato N, Masliah-Planchon J, Jongmans M, Abdul-Raman OA, Albrecht B, et al. Baraitser-Winter cerebrofrontofacial syndrome: delineation of the spectrum in 42 cases. Eur J Hum Genet 2015;23:292-301.

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12) Bergeron SE, Wedemeyer EW, Lee R, Wen KK, McKane M, Pierick AR, et al. Allele-specific effects of thoracic aortic aneurysm and dissection alpha-smooth muscle actin mutations on actin function. J Biol Chem 2011;286:11356-69.

13) Guo DC, Pannu H, Tran-Fadulu V, Papke CL, Yu RK, Avidan N, et al. Mutations in smooth muscle alpha-actin (ACTA2) lead to thoracic aortic aneurysms and dissections. Nat Genet 2007;39:1488-93.

14) Alajbegovic A, Holmberg J, Albinsson S. Molecular Regulation of Arterial Aneurysms: Role of Actin Dynamics and microRNAs in Vascular Smooth Muscle. Front Physiol 2017;8:569.