IllnessHeterotaxy - Situs inversus, differential diagnosis

NGS +

In heterotaxy syndrome, the internal organs in the chest and abdomen are abnormally arranged. Patients have complex birth defects involving the heart, lungs, liver, spleen, intestines and other organs. In rare cases, the alignment of the internal organs is completely reversed - situs inversus - which usually does not cause health problems unless it occurs as part of a syndrome that affects other parts of the body. Heterotaxy syndrome is an arrangement of the internal organs that lies between situs solitus and situs inversus; the condition is also called situs ambiguus. Heterotaxy can alter cardiac structures including that of the major blood vessels and the lungs and bronchi. Asplenia or polysplenia occur in the abdomen, and the liver may be misplaced sometimes with intestinal malrotation. Symptoms of heterotaxy may include cyanosis, difficulty breathing, increased risk of infection and problems with digestion, depending on the organs involved. The most serious complications are caused by critical congenital heart disease and biliary atresia. Some affected individuals have only mild health problems, but in infancy or childhood, the disease can be life-threatening even with treatment. Certain factors affecting pregnancy may also contribute to the risk of the child, such as diabetes mellitus, smoking, cocaine and certain chemicals. In rare cases, chromosomal abnormalities have been observed in heterotaxy, but mainly mutations in many different genes. At least 12% of patients with primary ciliary dyskinesia have heterotaxy syndrome. Yet, it usually occurs sporadically; in about 10% of cases, a close relative has a congenital heart defect without other symptoms (variable expressivity). When heterotaxy syndrome runs in families, it can be inherited in an autosomal dominant, recessive or X-linked manner. Because the molecular genetic yield is unknown, a negative DNA test result cannot exclude the clinical diagnosis.

Reference: https://www.ncbi.nlm.nih.gov/books/NBK1122/

https://www.ncbi.nlm.nih.gov/books/NBK1325/

https://www.ncbi.nlm.nih.gov/books/NBK1363/

https://www.ncbi.nlm.nih.gov/books/NBK368475/

• Alias: Situs inversus, Isomerismus
• Allelic: Atrioventricular septal defect, susceptibility to, 2 (CRELD1)
• Allelic: Congenital heart defects, nonsyndromic, 1, XL (ZIC3)
• Allelic: Dyslexia, susceptibility to, 1 (DNAAF4)
• Allelic: Hypoplastic left heart syndrome 2 (NKX2-5)
• Allelic: Hypothyroidism, congenital nongoitrous, 5 (NKX2-5)
• Allelic: Retinitis pigmentosa 23 (OFD1)
• Allelic: VACTERL association, XL (ZIC3)
• Atrial septal defect 7, with/-out AV conduction defects (NKX2-5)
• Atrioventricular septal defect, partial, with heterotaxy syndrome (CRELD1)
• Ciliary dyskinesia, primary, 1, with/-out situs inversus (DNAI1)
• Ciliary dyskinesia, primary, 10 (DNAAF2)
• Ciliary dyskinesia, primary, 13 (DNAAF1)
• Ciliary dyskinesia, primary, 14 (CCDC39)
• Ciliary dyskinesia, primary, 15 (CCDC40)
• Ciliary dyskinesia, primary, 16 (DNAL1)
• Ciliary dyskinesia, primary, 17 (CCDC103)
• Ciliary dyskinesia, primary, 18 (DNAAF5)
• Ciliary dyskinesia, primary, 19 (DNAAF11)
• Ciliary dyskinesia, primary, 2 (DNAAF3)
• Ciliary dyskinesia, primary, 20 (ODAD1 syn. CCDC114)
• Ciliary dyskinesia, primary, 22 (ZMYND10)
• Ciliary dyskinesia, primary, 23 (ODAD2 syn. ARMC4)
• Ciliary dyskinesia, primary, 25 (DNAAF49
• Ciliary dyskinesia, primary, 26 (CFAP298 syn. C21orf59)
• Ciliary dyskinesia, primary, 28 (SPAG1)
• Ciliary dyskinesia, primary, 3, with/-out situs inversus (DNAH5)
• Ciliary dyskinesia, primary, 35 (TTC25)
• Ciliary dyskinesia, primary, 36, XL (DNAAF6)
• Ciliary dyskinesia, primary, 37 (DNAH1)
• Ciliary dyskinesia, primary, 38 (CFAP300 syn. C11orf70)
• Ciliary dyskinesia, primary, 39 (LRRC56)
• Ciliary dyskinesia, primary, 40 (DNAH9)
• Ciliary dyskinesia, primary, 43 (FOXJ1)
• Ciliary dyskinesia, primary, 6 (NME8)
• Ciliary dyskinesia, primary, 7, with/-out situs inversus (DNAH11)
• Ciliary dyskinesia, primary, 9, with/-out situs inversus (DNAI2)
• Congenital heart defects, multiple types, 6 (GDF1)
• Conotruncal heart malformations, variable (NKX2-5)
• Heterotaxy, visceral, 1, XL (ZIC3)
• Heterotaxy, visceral, 2, AD (CFC1)
• Heterotaxy, visceral, 4, AD (ACVR2B)
• Heterotaxy, visceral, 5 (NODAL)
• Heterotaxy, visceral, 6, AR (CFAP53)
• Heterotaxy, visceral, 7, AR (MMP21)
• Heterotaxy, visceral, 8, AR (PKD1L1)
• Heterotaxy, visceral, 9, AR, with male infertility (MNS1)
• Heterotaxy, visceral; MONDO:0018677 (CFAP52)
• Joubert syndrome 10 (OFD1)
• Orofaciodigital syndrome I (OFD1)
• Right atrial isomerism [Ivemark] (GDF1)
• Simpson-Golabi-Behmel syndrome, type 2 (OFD1)
• Situs inversus [MONDO:0010029] (CFAP45)
• Tetralogy of Fallot (NKX2-5)
• Ventricular septal defect 3 (NKX2-5)