Primary ciliary dyskinesia: current state of the art

Ciliopathy spectrum expanded? Jeune syndrome associated with foregut dysmotility and malrotation

We report the association and surgical management of gastrointestinal dysmotility and malrotation with Jeune asphyxiating thoracic dystrophy (JATD), an autosomal recessive condition that often results in respiratory failure due to a small rib cage. A 4-month-old male with JATD presented with vomiting and aspiration pneumonitis compounding already severe respiratory morbidity. A contrast study revealed esophageal and gastric dysmotility with associated malrotation. This was treated surgically with good results. Some cases of JATD are caused by missense mutations in the gene IFT80, which encodes a protein implicated in the process of intraflagellar transport of primary cilia. We speculate that these abdominal complications might also be part of the extending spectrum of ciliopathy.

Mutations in radial spoke head protein genes RSPH9 and RSPH4A cause primary ciliary dyskinesia with central-microtubular-pair abnormalities

Primary ciliary dyskinesia (PCD) is a genetically heterogeneous inherited disorder arising from dysmotility of motile cilia and sperm. This is associated with a variety of ultrastructural defects of the cilia and sperm axoneme that affect movement, leading to clinical consequences on respiratory-tract mucociliary clearance and lung function, fertility, and left-right body-axis determination. We performed whole-genome SNP-based linkage analysis in seven consanguineous families with PCD and central-microtubular-pair abnormalities. This identified two loci, in two families with intermittent absence of the central-pair structure (chromosome 6p21.1, Zmax 6.7) and in five families with complete absence of the central pair (chromosome 6q22.1, Zmax 7.0). Mutations were subsequently identified in two positional candidate genes, RSPH9 on chromosome 6p21.1 and RSPH4A on chromosome 6q22.1. Haplotype analysis identified a common ancestral founder effect RSPH4A mutation present in UK-Pakistani pedigrees. Both RSPH9 and RSPH4A encode protein components of the axonemal radial spoke head. In situ hybridization of murine Rsph9 shows gene expression restricted to regions containing motile cilia. Investigation of the effect of knockdown or mutations of RSPH9 orthologs in zebrafish and Chlamydomonas indicate that radial spoke head proteins are important in maintaining normal movement in motile, "9+2"-structure cilia and flagella. This effect is rescued by reintroduction of gene expression for restoration of a normal beat pattern in zebrafish. Disturbance in function of these genes was not associated with defects in left-right axis determination in humans or zebrafish.

Ultrastructural abnormalities of respiratory cilia: a 25-year experience

CONTEXT

Ciliary dyskinesia is a rare, but significant, cause of chronic respiratory infections, and transmission electron microscopy is a critical adjunct to making the diagnosis.

OBJECTIVE

To investigate a single institution's experience with patients demonstrating abnormal ciliary ultrastructure.

DESIGN

Retrospective clinicopathologic review of 278 bronchial or nasal turbinate brushings or biopsies from 1983 through 2007.

RESULTS

There were 12 women and 9 men (mean age, 19.6 years; range, 1-54 years) with abnormal ciliary ultrastructure. Clinical history was unavailable in 3 patients, 15 (83%) of 18 patients presented with chronic or recurrent upper respiratory infections, and 3 (17%) presented with infertility. Seven (39%) of 18 patients had findings of Kartagener syndrome with situs inversus, dextrocardia, and bronchiectasis. Truncation or absence of inner or outer dynein arms occurred in 15 (71%) of 21 cases, and 5 (24%) revealed transposition defects with displacement of the central microtubules and peripheral doublets in 9 + 0 and 8 + 1 patterns. Radial spoke defects with microtubular disarray occurred in 4 (19%) of 21 cases. Compound cilia with multiple axonemes within a single outer sheath and supernumerary microtubules each occurred in 2 (10%) of the cases. Random ciliary orientation was also found in 2 (10%) of the cases, and dense granular basal body inclusions occurred in 1 case (5%). Multiple abnormalities occurred in 6 (29%) of the 21 cases.

CONCLUSIONS

Most patients presented with chronic respiratory tract infections or infertility. Dynein arm defects, transposition defects, and radial spoke defects were the most commonly encountered abnormal findings. Less-frequent abnormal findings included compound cilia, supernumerary microtubules, and dense granular basal body inclusions.

Successful twin birth following blastocyst culture of embryos derived from the immotile ejaculated spermatozoa from a patient with primary ciliary dyskinesia: a case report

PURPOSE

To describe the ultrastructure of spermatozoa from a patient with complete asthenozoospermia that resulted in live births following blastocyst culture.

MATERIALS AND METHODS

Analyses of spermatozoa from a 36 year old patient were performed using light and electron microscopy. The hypo-osmotic swelling test was used to select spermatozoa for intracytoplasmic sperm injection. Embryos were cultured to the blastocyst stage.

RESULTS

100% of the spermatozoa had dynein arm deficiency with secondary defects varying from 3-17%. Six oocytes were injected; five fertilized normally and one was digynic. All five zygotes formed good quality blastocysts. Three blastocysts were cryopreserved and two blastocysts were transferred. Twin females were born at 37 weeks.

CONCLUSIONS

The hypo-osmotic swelling test can be used to select viable immotile ejaculated spermatozoa from a patient with dynein arm deficiency and can produce excellent fertilization rates and blastocyst development resulting in live births.

Structural and functional lung disease in primary ciliary dyskinesia

BACKGROUND

High-resolution CT (HRCT) scan data on primary ciliary dyskinesia (PCD) related lung disease are scarce.

STUDY OBJECTIVES

We evaluated the lung disease in children and adults with PCD by a modified Brody composite HRCT scan score to assess the prevalence of the structural abnormalities; to evaluate the correlation among HRCT scan scores, spirometry findings, and clinical data; and to compare the PCD scores with those of age-matched and sex-matched cystic fibrosis (CF) patients.

PATIENTS AND METHODS

Twenty PCD patients (age range, 4.6 to 27.5 years) underwent HRCT scanning, spirometry, and deep throat or sputum culture. A modified Brody score was used to assess bronchiectasis, mucous plugging, peribronchial thickening, parenchyma abnormalities, and mosaic perfusion.

RESULTS

The total HRCT scan score was 6% of the maximal score (range, 0.5 to 25.5). Subscores were as follows: bronchiectasis, 5.6%; mucous plugging, 5.6%; peribronchial thickening, 8.3%; parenchyma, 3%; and mosaic perfusion, 0%. The prevalence of lung changes were as follows: bronchiectasis, 80%; peribronchial thickening, 80%; mucous plugging, 75%; parenchyma, 65%; and mosaic perfusion, 45%. Sixteen of 19 PCD patients had positive culture findings, and the most common pathogen found was Haemophilus influenzae (84%). The total HRCT scan score was significantly related to age (p = 0.006), FEV(1) (p = 0.02), and FVC (p = 0.02). The bronchiectasis subscore was significantly related to FEV(1) (p = 0.04) and FVC (p = 0.03). In CF patients, the total HRCT scan score was significantly higher than that in PCD patients (p = 0.02).

CONCLUSIONS

PCD patients show significantly lower pulmonary HRCT scan scores than CF patients. The PCD total and bronchiectasis scores correlate with spirometry findings. The PCD HRCT scan score might be used for longitudinal assessment and/or represent an outcome surrogate in future studies.