Retinitis Pigmentosa, X-Linked, And Sinorespiratory Infections, With Or Without Deafness

A number sign (#) is used with this entry because X-linked retinitis pigmentosa with recurrent respiratory infections is caused by mutation in the RPGR gene (312610).

Clinical Features

In a family with X-linked retinitis pigmentosa with recurrent respiratory infections, van Dorp et al. (1992) identified, by electron microscopy, nasal ciliary abnormalities in some affected males, consisting of deficient inner dynein arms, incomplete microtubules, and disorientation of cilia, associated with recurrent respiratory infections indistinguishable from immotile cilia syndrome (see 244400). Infertility of the affected males was not a feature. Van Dorp et al. (1992) raised the possibility that ciliary abnormalities in XLRP patients (see 300455) may be associated specifically with the RP3 locus mutation. Abnormalities of cilia have been reported in X-linked and autosomal types of RP, including Usher syndrome (276900, 276901) (Arden and Fox, 1979; Fox et al., 1980; Hunter et al., 1988).

Zito et al. (2003) described a family with X-linked retinitis pigmentosa associated with hearing loss, sinusitis, and chronic recurrent respiratory tract infections. The 4 carrier females and 3 affected males were myopic but female carriers were asymptomatic, had normal fields to confrontation, and showed sparse peripheral intraretinal pigmentation. However, additional systemic symptoms were observed in both hemizygous males and heterozygous females. One of the most striking and obvious additional features was the requirement of hearing aids by both affected males and female carriers. Both had severe recurrent ear infections from early childhood continuing into adulthood. Because of hearing loss in the high frequencies, the audiogram was considered consistent with sensorineural hearing loss, although a conductive hearing component may have contributed. Affected males and carrier females suffered from severe recurrent sinus infections. The 3 affected males had chronic recurrent chest infections starting in early childhood, with episodes of bronchitis, which continued into adulthood. The possibility of renal failure being part of the clinical picture was suggested by its occurrence in 1 affected male. The phenotype overlapped those described for primary ciliary dyskinesia and Usher syndrome (276900) and provided support for an essential ciliary function for RPGR in the retina and other tissues.

Iannaccone et al. (2003) reported 2 brothers with X-linked retinitis pigmentosa, hearing loss, recurrent otitis media, and recurrent upper respiratory infections. A deceased great-great maternal uncle had been diagnosed with Usher syndrome, and the maternal grandmother had 'late-onset' retinitis pigmentosa and sensorineural hearing loss. In addition to classic RP, both affected brothers had recurrent ear infections requiring tube placement and mild hearing loss. A mutation in the RPGR gene (312610.0020) was identified in the brothers, the mother, and the maternal grandmother.

Moore et al. (2006) reported 2 brothers, born of a mother with retinitis pigmentosa, who presented in early childhood with respiratory symptoms characterized by chronic sinusitis, serous otitis, and recurrent episodes of bronchitis associated with severe atelectasis that led to partial lobectomy in both children when they were 14 years old. Radiologic and laboratory evaluation revealed findings typical for primary ciliary dyskinesia, including diffuse bronchiectasis, distal obstruction without hypoxemia, and the presence of Hemophilus influenzae. Pure-tone audiometry revealed a predominantly high-frequency hearing impairment in the older brother; results were normal in the younger brother and their mother. Both motile and immotile cilia were detected in samples from the older brother, whereas no ciliary beating was observed in the younger brother's samples. Transmission electron microscopy analysis showed numerous abnormal cilia in which different axonemal structures were missing; taken with the typical clinical features, this led to the diagnosis of primary ciliary dyskinesia in both brothers. Neither their parents nor other relatives had a history of respiratory disease; ciliary motility studies of nasal ciliated cells from the mother were normal. Ophthalmologic examination confirmed the diagnosis of RP in both brothers.

Molecular Genetics

In the family with X-linked retinitis pigmentosa with recurrent respiratory infections described by van Dorp et al. (1992), Dry et al. (1999) identified an IVS5+1G-T splice site mutation in the RPGR gene (312610.0016).

In a family in which affected males in an X-linked recessive pedigree pattern had retinitis pigmentosa associated with impaired hearing and sinorespiratory infections, Zito et al. (2003) identified a 2-bp deletion, 845delTG, in exon 8 of the RPGR gene (312610.0019).

In a mother with retinitis pigmentosa and her 2 sons with primary ciliary dyskinesia and retinitis pigmentosa, Moore et al. (2006) identified a 57-bp deletion in the RPGR gene (312610.0023).