Defects in laterality with emphasis on heterotaxy syndromes with asplenia and polysplenia: an autopsy case series at a single institution

Locally invasive cholangiocarcinoma causing gastric outlet obstruction in heterotaxy syndrome: A case report and review of literature

Heterotaxy syndrome is a disease of embryo development resulting in abnormal distribution of thoracic and abdominal organs across the left-right axis. In this case, A 77-year-old gentleman was admitted with gastric outlet obstruction secondary to cholangiocarcinoma. This is on a background of heterotaxy syndrome, specifically situs ambiguus. The patient's anatomical variations included a right-sided stomach, midline liver, and asplenia. Due to variant anatomy and risk of aspiration; endoscopy was abandoned in favor of surgical bypass via a gastrojejunostomy. Although technically challenging, complex upper abdominal surgery in heterotaxy syndrome has been described in the literature. Variations in anatomy observed in heterotaxy syndrome may render patients ineligible for resection of cholangiocarcinoma and increase the risk of complications. Careful preoperative planning with imaging and meticulous intraoperative dissection is required.

Heterotaxy Syndrome with Increased Nuchal Translucency and Normal Karyotype Associated with Complex Systemic Venous Return. Ultrasound Diagnosis with Autopsy Correlation

Background: Prenatal ultrasound (US) detection of heterotaxy syndrome can be challenging, especially in identifying cardiovascular and associated anomalies. We present a new case of heterotaxy syndrome with anomalous systemic venous return (ASVR) fully displayed at autopsy. Case report: Left heterotaxy syndrome was diagnosed in a 19 weeks' of gestation fetus with right-sided stomach. The heart showed both ventricles with left morphology, a large ventricular septal defect, persistent left superior vena cava draining into the coronary sinus, ASVR with interrupted inferior vena cava (IVC) and azygous continuation. Autopsy dissection further identified the azygous draining into the left lower pulmonary vein (LLPV). Prenatal a-CGH on villous sampling showed 22q13.1 microduplication inherited from the father, not contributory to the phenotype. Conclusion/discussion: Heterotaxy syndrome requires US accuracy for anomaly identification, as they allow legal termination of pregnancy. Our case is unusual as IVC drained into the azygous vein and then into the LLPV.

Characterization of phenotypic spectrum of fetal heterotaxy syndrome by combining ultrasound and magnetic resonance imaging

OBJECTIVE

Heterotaxy or isomerism of the atrial appendages is a congenital disorder with variable presentation, associated with both cardiac and non-cardiac anomalies, which may have a serious impact on fetal outcome. The aim of this exploratory study was to assess the value of fetal magnetic resonance imaging (MRI), as a complementary tool to ultrasound, for describing the morphological spectrum encountered in heterotaxy.

METHODS

This retrospective study included 27 fetuses that underwent fetal MRI following prenatal suspicion of heterotaxy on ultrasound from 1998 to 2019 in a tertiary referral center. Heterotaxy was classified as left atrial isomerism (LAI) or right atrial isomerism (RAI) based on fetal echocardiography (FE) examination. In addition to routine prenatal ultrasound, fetal MRI was offered routinely to enhance the diagnosis of non-cardiac anomalies, which might have been missed on ultrasound. Prenatal findings on ultrasound, FE and MRI were reviewed systematically and compared with those of postnatal imaging and autopsy reports.

RESULTS

Twenty-seven fetuses with heterotaxy and cardiovascular pathology, of which 19 (70%) had LAI and eight (30%) had RAI, were included. Seven (7/19 (37%)) fetuses with LAI had normal intracardiac anatomy, whereas all fetuses with RAI had a cardiac malformation. All 27 fetuses had non-cardiac anomalies on fetal MRI, including situs and splenic anomalies. In 12/19 (63%) fetuses with LAI, a specific abnormal configuration of the liver was observed on MRI. In three fetuses, fetal MRI revealed signs of total anomalous pulmonary venous connection obstruction. An abnormal bronchial tree pattern was suspected on prenatal MRI in 6/19 (32%) fetuses with LAI and 3/8 (38%) fetuses with RAI.

CONCLUSIONS

Visualization on MRI of non-cardiac anomalies in fetuses with suspected heterotaxy is feasible and can assist the complex diagnosis of this condition, despite its limitations. This modality potentially enables differentiation of less severe cases from more complex ones, which may have a poorer prognosis. Fetal MRI can assist in prenatal counseling and planning postnatal management. © 2021 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Human Laterality Disorders: Pathogenesis, Clinical Manifestations, Diagnosis, and Management

Human laterality disorders comprise a group of diseases characterized by abnormal location (situs) and orientation of thoraco-abdominal organs and vessels across the left-right axis. Situs inversus totalis is mirror image reversal of thoraco-abdominal organs/great vessels. Situs ambiguus, better known as heterotaxy, is abnormal arrangement of thoraco-abdominal organs across the left-right axis excluding situs inversus totalis. Heterotaxy, also referred to as atrial or atrial appendage isomerism, is characterized by abnormal location of left-sided or right-sided organs with loss of asymmetry of normally paired asymmetric organs. It is associated with a variety of anomalies involving the heart, great vessels, lungs and intra-abdominal organs. Right and left atrial isomerism are associated with multiple complex congenital cardiac and vascular anomalies, many of which are lethal when untreated. Isomerism may also affect the lungs, spleen, liver, gall bladder, and intestines. Innovative surgical therapy of heterotaxy/isomerism has reduced early mortality and markedly improved long-term prognosis.

Congenitally Malformed Hearts: Aspects of Teaching and Research Involving Medical Students

To appreciate congenital heart disease fully, a detailed understanding of the anatomical presentation, as well as the physiology, is required. This is often introduced at an advanced stage of training. Professor Anderson has been influential in the Clinical Anatomy Intercalated BSc programme at the University of Birmingham, in particular in his teaching on Sequential Segmental Analysis. This article describes the experiences of the latest cohort of students on this programme, who undertook varying research projects using the Birmingham Cardiac Archive, with the guidance of Professor Anderson. The projects outlined include various aspects of isomerism, encompassing both the cardiac and abdominal manifestations, as well as details of congenitally corrected transposition of the great arteries and prenatally diagnosed right aortic arch and double arch. These studies all aimed to increase the knowledge base of their respective cardiac malformations and provide a basis for further research.

Senning Procedure for Physiological Atrial Inversion With Left Atrial Isomerism

We present the case of an infant with left atrial isomerism with complex pulmonary and systemic venous connections that resulted in physiological parallel circulation in the setting of ventriculoarterial concordance who was surgically treated using the Senning procedure. This case highlights a rare cause for cyanosis due to poor mixing from a parallel circulation and an issue with nomenclature. (Level of Difficulty: Advanced.).

Characterisation of computed tomography angiography findings in paediatric patients with heterotaxy

BACKGROUND

Heterotaxy refers to the abnormal arrangement of organs across the left-right axis and is typically associated with complex cardiovascular malformations.

OBJECTIVE

To characterise the range of cardiac and extracardiac CT angiography findings in children with heterotaxy using the latest nomenclature consensus and to compare the different types of isomerism.

MATERIALS AND METHODS

We retrospectively analysed the data of 64 consecutive paediatric patients referred to our tertiary paediatric cardiovascular centre who underwent CT angiography for the evaluation of known or suspected heterotaxy within a 52-month period.

RESULTS

Right atrial isomerism was identified in 44 (69%) children, while left atrial isomerism was identified in 18 (28%) children. Atrial appendage anatomy and situs could not be determined in 2 children (3%). Associated heart defects included complete atrioventricular canal (CAVC) in 51 (80%) children, total anomalous pulmonary venous return in 43 (67%) and pulmonary atresia in 23 (36%). The bronchial branching pattern corresponded to atrial appendage morphology in all children except in the two in whom atrial appendage morphology could not be defined. In children with right atrial isomerism, the most common associated abnormalities were CAVC (n=41, 93%) and asplenia (n=34, 77%), while in those with left atrial isomerism, the most common associated abnormalities were polysplenia (n=17, 94%) and an interrupted inferior vena cava with azygos continuation (n=15, 83%).

CONCLUSION

CT angiography provides useful cardiovascular and extracardiac data on heterotaxy, which frequently involves a pattern of side-related findings but has great anatomical variability.

Polysplenia Syndrome as a Risk Factor for Early Progression of Pulmonary Hypertension

BACKGROUND

Recent progress in surgical and intensive care has improved the prognosis of congenital heart disease (CHD) associated with heterotaxy syndrome. Less is known, however, about pulmonary vascular complications in these patients. Methods and Results: We reviewed medical records of 236 patients who were diagnosed with polysplenia syndrome at 2 institutions for pediatric cardiology in Japan from 1978 to 2015. We selected and compared the clinical records of 16 patients with polysplenia who had incomplete atrioventricular septal defect (AVSD) as the polysplenia group, and 22 age-matched patients with incomplete AVSD without any syndromes including polysplenia as the control group. Although the severity of systemic to pulmonary shunt was not significantly different between the groups, mean pulmonary artery pressure (mPAP) and pulmonary vascular resistance index (PVRI) were significantly higher in the polysplenia group than the control (mPAP, 37.3 vs. 19.1 mmHg, P=0.001; PVRI, 5.7 vs. 1.4 WU∙m², P=0.014) before surgical intervention. On regression analysis, polysplenia influenced the development of pulmonary hypertension (PH) regardless of age at evaluation or degree of systemic to pulmonary shunt in the patients with incomplete AVSD.

CONCLUSIONS

Polysplenia syndrome is an independent risk factor for CHD-associated PH. Earlier intervention may be required to adjust the pulmonary blood flow in polysplenia syndrome with CHD to avoid the progression of PH.

Antenatal ultrasound diagnosis of small bowel non-rotation in complex left isomerism: a case report

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A rare case of mixed isomerism and antenatally diagnosed non-rotation of bowel is reported.

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Features of bowel non-rotation should be sought antenatally in cases of isomerism.

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Mixed isomerism and postnatal sequelae should be considered when right and left sided pathology coexist.z

Presentation of case

A multiparous expectant mother was referred to our tertiary unit at 23 weeks with a complex fetal cardiac anomaly in the context of suspected heterotaxy syndrome. The cardiac findings were consistent with isomerism: the fetal cardiac position was levocardia with a single functioning double outlet ventricle and AV valve, pulmonary stenosis, and interrupted inferior vena cava (IVC) with azygous continuation. The fetal abdominal situs was also altered, with the stomach to the right, and the hepatobiliary system midline to left. The spleen was not identified antenatally or postnatally. At 36 weeks, ultrasound revealed an abnormal bowel pattern with small bowel loops on the right side of the abdomen and large bowel on the left, suggesting a diagnosis of non- rotation. The infant was delivered vaginally at 39 weeks. The cardiac diagnosis and non-rotation of the small bowel were confirmed by postnatal echocardiography and contrast fluoroscopy.

Discussion

Heterotaxy syndrome is traditionally classified into right or left isomerism depending on how and where the organs are anatomically arranged. The case presented here demonstrates mixed laterality and prenatal ultrasound features of non-rotation.

Conclusion

It is important to be informed of the embryological variants of isomerism and actively seek antenatal evidence of bowel non-rotation in such cases.

RPSA, a candidate gene for isolated congenital asplenia, is required for pre-rRNA processing and spleen formation in Xenopus

A growing number of tissue-specific inherited disorders are associated with impaired ribosome production, despite the universal requirement for ribosome function. Recently, mutations in RPSA, a protein component of the small ribosomal subunit, were discovered to underlie approximately half of all isolated congenital asplenia cases. However, the mechanisms by which mutations in this ribosome biogenesis factor lead specifically to spleen agenesis remain unknown, in part due to the lack of a suitable animal model for study. Here we reveal that RPSA is required for normal spleen development in the frog, Xenopus tropicalis Depletion of Rpsa in early embryonic development disrupts pre-rRNA processing and ribosome biogenesis, and impairs expression of the key spleen patterning genes nkx2-5, bapx1 and pod1 in the spleen anlage. Importantly, we also show that whereas injection of human RPSA mRNA can rescue both pre-rRNA processing and spleen patterning, injection of human mRNA bearing a common disease-associated mutation cannot. Together, we present the first animal model of RPSA-mediated asplenia and reveal a crucial requirement for RPSA in pre-rRNA processing and molecular patterning during early Xenopus development.

Left Upper-Quadrant Appendicitis in a Patient with Congenital Intestinal Malrotation and Polysplenia

Patient: Female, 13

Final Diagnosis: Left upper quadrant appendicitis

Symptoms: Left upper quadrant abdominal pain

Medication: —

Clinical Procedure: Laparoscopic ladd’s procedure

Specialty: Surgery

Prenatal Findings in Left Atrial Isomerism and an Overview of Heterotaxy Syndrome

Heterotaxy syndrome is a rare, complex disorder involving structural cardiac defects in combination with symmetrical development of abdominal viscera that are normally asymmetrical organs. The vast assortment of cardiac manifestations with accompanying abdominal visceral variations determines the prognosis of heterotaxy syndrome. This case study provides an example of the management of this disease, which is unique to the patient. This is a case report of heterotaxy syndrome diagnosed in utero at 29 weeks and 4 days.

Human B-cell memory is shaped by age- and tissue-specific T-independent and GC-dependent events

Switched and IgM memory B cells execute different and noninterchangeable functions. We studied memory B cells in children of different ages, in peripheral blood and spleen and compared them with those of children born asplenic or unable to build germinal centers. We show that, whereas switched memory B cells are mostly generated in the germinal centers at all ages, IgM memory B cells can be distinct in three types with different developmental history. Innate IgM memory B cells, the largest pool in infants, are generated in the spleen by a germinal center-independent mechanism. With age, if the spleen is present and germinal centers are functional, innate IgM memory B cells are remodelled and accumulate somatic mutations. The third type of IgM memory B cell is a by-product of the germinal center reaction. Our data suggest that the B-cell memory developmental program is implemented during the first 5-6 years of life.

Prevalence of Noncardiac and Genetic Abnormalities in Neonates Undergoing Cardiac Operations: Analysis of The Society of Thoracic Surgeons Congenital Heart Surgery Database

BACKGROUND

Among patients with congenital heart disease (CHD), the coexistence of noncardiac congenital anatomic abnormalities (NC), genetic abnormalities (GA), and syndromes (S) may influence therapeutic strategies and outcomes. The appreciated prevalence of these abnormalities has risen because increased screening and improved diagnostic precision enable identification of these comorbidities in a larger fraction of neonates with CHD. We examined the contemporary prevalence and distribution of NC/GA/S across diagnostic groups among neonates undergoing cardiac operations using a large nationally representative clinical registry.

METHODS

The Society of Thoracic Surgeons Congenital Heart Surgery Database (STS-CHSD) was queried to identify neonates (≤30 days) who underwent index cardiac operations from 2010 to 2013. The fundamental cardiac diagnosis was used to identify 10 diagnostic groups. The prevalence of NC/GA/S was reported across each group.

RESULTS

The cohort included 15,376 index neonatal operations from 112 centers. Overall, 18.8% (2,894 of 15,376) of operations were performed in neonates with NC/GA/S. Patients with atrioventricular septal defect (212 of 357 [59.4%]), interrupted aortic arch (248 of 567 [43.7%]), truncus arteriosus (204 of 554 [36.8%]), and tetralogy of Fallot (417 of 1,383 [30.2%]) had the highest prevalence of NC/GA/S abnormalities, whereas those with transposition of the great arteries (111 of 2,778 [4.0%]) had the lowest prevalence. The most commonly identified NC/GA/S included heterotaxy (597 of 15,376 [3.9%]), DiGeorge syndrome or 22q11 deletion (550 of 15,376 [3.6%]), Down syndrome or trisomy 21 (318 of 15, 376 [2.1%]), intestinal malrotation (220 of 15,376 [1.4%]), and Turner syndrome or 45XO (189 of 15,376 [1.2%]).

CONCLUSIONS

The prevalence of NC/GA/S varies widely across CHD diagnostic groups. This information may be useful for patient counseling, recommendations for screening for anomalies and genetic disorders, and perioperative management.

A 0.5-Mbp deletion on bovine chromosome 23 is a strong candidate for stillbirth in Nordic Red cattle

Background

A whole-genome association study of 4631 progeny-tested Nordic Red dairy cattle bulls using imputed next-generation sequencing data revealed a major quantitative trait locus (QTL) that affects birth index (BI) on Bos taurus autosome (BTA) 23. We analyzed this QTL to identify which of the component traits of BI are affected and understand its molecular basis.

Results

A genome-wide scan of BI in Nordic Red dairy cattle detected major QTL on BTA6, 14 and 23. The strongest associated single nucleotide polymorphism (SNP) on BTA23 was located at 13,313,896 bp with \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$- \log_{10} ({\text{p}}) = 50.63$$\end{document}-log10(p)=50.63. Analyses of component traits showed that the QTL had a large effect on stillbirth. Based on the 10 most strongly associated SNPs with stillbirth, we constructed a haplotype. Among this haplotype’s alleles, HAP_QTL had a large negative effect on stillbirth. No animals were found to be homozygous for HAP_QTL. Analysis of stillbirth records that were categorized by carrier status for HAP_QTL of the sire and maternal grandsire suggested that this haplotype had a recessive mode of inheritance. Illumina BovineHD BeadChip genotypes and genotype intensity data indicated a chromosomal deletion between 12.28 and 12.81 Mbp on BTA23. An independent set of Illumina Bovine50k BeadChip genotypes identified a recessive lethal haplotype that spanned the deleted region.

Conclusions

A deleted region of approximately 500 kb that spans three genes on BTA23 was identified and is a strong candidate QTL with a large effect on BI by increasing stillbirth.

Electronic supplementary material

The online version of this article (doi:10.1186/s12711-016-0215-z) contains supplementary material, which is available to authorized users.

Screening and Treatment of Intestinal Rotational Abnormalities in Heterotaxy: A Systematic Review and Meta-Analysis

OBJECTIVE

To assess the role of screening and prophylactic surgery for intestinal rotational abnormalities (IRAs) in asymptomatic patients with heterotaxy.

STUDY DESIGN

PubMed, Embase, and Cinahl were searched electronically to determine the overall incidence of IRAs in heterotaxy; the detection rate of IRAs associated with screening; the incidence of midgut volvulus in patients without screening; and the incidence of morbidity and mortality after prophylactic and emergency Ladd procedures. Relevant data were computed with a meta-analysis of proportions. Between-study heterogeneity was assessed with the I(2) statistic.

RESULTS

From 276 papers identified, 24 studies with a total of 1433 patients with heterotaxy were included for systematic review. No randomized study was identified. True incidence of IRA in heterotaxy could not be ascertained through meta-analysis. In patients who underwent screening, the incidence of IRA was 58%. Acute midgut volvulus occurred in 5.8% of those who did not undergo screening. Postoperative mortality after Ladd procedure mainly was associated with cardiac insufficiency, and overall it was significantly greater in the emergency group compared with the prophylactic group (18% vs 5.6%). The complication rate also was greater in case of emergency vs prophylactic abdominal surgery (27% vs 16%); adhesional small bowel obstruction was the most common complication overall (6%).

CONCLUSION

The screen-detected incidences of IRA and acute midgut volvulus were significantly greater in heterotaxy than the normal population. Prophylactic Ladd procedure was associated with less morbidity and mortality compared with emergency surgery. A long-term prospective randomized trial is needed to define the indication for screening and prophylactic treatment of IRA in heterotaxy.

Antenatally diagnosed right-sided stomach (dextrogastria): A rare rotational anomaly

AIM

Antenatal detection of right-sided stomach (dextrogastria) is rare, and its significance in regards to intestinal rotation is unclear. We aimed to review all cases of antenatally-diagnosed dextrogastria in our regional fetal medicine unit over 10years.

METHODS

A retrospective case-note review of patients identified from a prospectively-maintained database was performed.

RESULTS

Twenty cases of antenatally-diagnosed dextrogastria were identified from 2004 to 2014. There were 8 terminations and 1 intra-uterine death. One patient has no post-natal information obtainable. Ten infants were live-born, and 2 died secondary to cardiac disease in the neonatal period. All had significant cardiac/vascular anomaly on postnatal assessment, including the 3 neonates in whom dextrogastria was the only antenatal finding. Two neonates developed bilious vomiting and underwent Ladd's procedure. Operative findings were dextrogastria/malrotation in both. A third child had gastro-oesophageal reflux, and contrast demonstrated stable duodenal/midgut position. This child has not developed symptoms attributable to malrotation and not undergone surgery. All 3 of these infants had asplenia or polysplenia and were managed with antibiotic prophylaxis/immunisation. Five children in the series were not investigated for malrotation and have not come to surgical attention (one is known to be asplenic).

CONCLUSION

Antenatally-detected dextrogastria, even if apparently isolated, was always associated with postnatal significant cardiovascular anomaly, splenic abnormality or situs inversus. This may be important for antenatal counselling. We currently recommend postnatal echocardiography and splenic assessment, but reserve GI investigation/intervention for symptomatic malrotation owing to potential significant cardiac comorbidity.

Asplenia in children with congenital heart disease as a cause of poor outcome

The absence of a spleen is a well-known risk factor for severe bacterial infections, especially due to encapsulated bacteria. Congenital asplenia can be part of multiple congenital abnormalities as in heterotaxy including Ivemark syndrome with congenital anomalies of the heart or great vessels, or it can be isolated, which is extremely rare. In these cases, asplenia is an important factor effecting mortality. In this report, the clinical courses of five children with asplenia and concomitant minor or complex cardiac anomalies are presented. The ages of the children ranged between 1.5 and 17 months at the time of diagnosis. All of the cases had had a history of hospitalisation for infectious diseases before the diagnosis. The patient who was diagnosed at 17 months old had a history pneumonia, urinary tract infection, and bacterial meningitis beginning at five months old. Three children had complex cardiac anomalies, one child had ventricular septal defect, and one child had atrial septal defect. Howell-Jolly bodies were determined in peripheral blood smear in all of the patients. The diagnoses of asplenia were confirmed with spleen scintigraphy. One of the patients with complex cardiac anomalies died a short time after diagnosis, because of cardiac failure. The rest of the four patients were vaccinated for encapsulated bacteria and were taken under antibiotic prophylaxis. These children did not need hospitalisation for infectious diseases during the follow-up period (5-40 months). In asplenic children, early diagnosis, antibiotic prophylaxis, and immunisation for encapsulated bacteria can decrease the risk of morbidity and mortality.

Heterotaxy Polysplenia Syndrome In An Adult With Unique Vascular Anomalies: Case Report With Review Of Literature

The pattern of anatomical organization of the thoraco-abdominal visceral and vascular structures which is not the expected normal arrangement, is called as situs ambiguous or heterotaxy syndrome. Patients with heterotaxy syndrome exhibit a wide spectrum of anatomical variations involving thoraco-abdominal structures. We present here an incidental finding of heterotaxy syndrome associated with unique vascular anomalies in a 35 year old male patient evaluated initially for nephrolithiasis by ultrasonography, and intravenous pyelography. Further evaluation by multidetector row computed tomography showed bilateral bilobed lungs with hyparterial bronchi, cardiac apex to the left, five branches from left-sided aortic arch with retroesophageal right subclavian artery, interrupted inferior vena cava with azygos continuation, left renal vein continuing as hemiazygos vein and replaced common hepatic artery arising from the superior mesenteric artery. Other vascular anomalies include right internal iliac vein joining the left common iliac vein and precaval course of the single main right renal artery. Anomalies involving abdominal organs include right-sided stomach, midline liver, multiple splenules (polysplenia) in right upper quadrant of abdomen, short truncated pancreas, intestinal malrotation, inversion of superior mesenteric vessels and a preduodenal portal vein. To the best of our knowledge this is the first report of association of left renal vein continuing as hemiazygos vein, precaval right renal artery and anomalous branching pattern of aortic arch with heterotaxy syndrome.

A case report of primary ciliary dyskinesia, laterality defects and developmental delay caused by the co-existence of a single gene and chromosome disorder

Background

Primary ciliary dyskinesia (PCD) is a rare autosomal recessive disorder characterised by abnormal ciliary motion and impaired mucociliary clearance, leading to recurrent respiratory infections, sinusitis, otitis media and male infertility. Some patients also have laterality defects. We recently reported the identification of three disease-causing PCD genes in the Irish Traveller population; RSPH4A, DYX1C1 and CCNO. We have since assessed an additional Irish Traveller family with a complex phenotype involving PCD who did not have any of the previously identified PCD mutations.

Case presentation

In this study we report on a family with three children with PCD and various laterality defects. In addition, one child (V:1) has mild-to-moderate developmental delay and one child has speech delay (V:2). Developmental delay is not usually associated with PCD and is likely to be caused by an additional genetic abnormality. Transmission electron microscopy showed variable inner and outer dynein arm defects. Exome sequencing identified a homozygous missense variant in CCDC103 (c.461A > C; p.His154Pro) as the most likely cause of the PCD and laterality defects in this family. However, as mutation in CCDC103 would not account for the developmental delay, array comparative genomic hybridisation was undertaken and identified a maternally inherited gain of ~1.6 Mb (chr17:34,611,352-36,248,918). Gains at this locus are associated with 17q12 duplication syndrome which includes speech and language delay.

Conclusion

We report on a variable and complex phenotype caused by the co-inheritance of a single gene mutation in CCDC103 and a microduplication at 17q12, both on chromosome 17. The co-existence of a single gene and chromosome disorder is unusual but accounts for the spectrum of clinical features in this family. In addition, our study brings the total number of PCD genes in the Irish Traveller population to four and we suspect additional PCD genes are yet to be identified. Although, on a global scale, PCD is associated with extensive genetic heterogeneity, finding such a high number of causative PCD genes within the relatively small Irish Traveller population was unexpected.

Electronic supplementary material

The online version of this article (doi:10.1186/s12881-015-0192-z) contains supplementary material, which is available to authorized users.