PMC6857777_01
Family pedigrees. Shown are 12 families segregating IRD and additional systemic diseases. Filled symbols represent affected individuals, whereas clear symbols represent unaffected individuals. A double line represents consanguinity. Patients recruited for this study are marked by numbers. In mutation names, * represents a termination codon. +, wild-type (wt) allele; m, mutant allele; RP, retinitis pigmentosa; HL, hearing loss; FMF, familial Mediterranean fever; DI, diabetes insipidus; CGD, chronic granulomatous disease; ARB, autosomal recessive bestrophinopathy; ID, intellectual disability; CRD, cone-rod dystrophy; PCD, primary ciliary dyskinesia; CSNB, congenital stationary night blindness.
mv-v25-691-f1.jpg
PMC6857777_01_mv-v25-691-f1.jpg
f1
Family history revealed that his maternal grandfather had been diagnosed with RP (Figure 1). Data regarding his hearing status were not available (Figure 1). ERG was consistent with rod-cone disease, i.e., RP (Figure 1). ARB (Table 1). A causative mutation for ichthyosis was not found; however, intrafamilial marriage for several generations in this family, and the occurrence of additional affected individuals in previous generations, supports an AR inheritance mode (Figure 1). HL led to an initial diagnosis of USH. However, further questioning revealed the existence of non-syndromic RP in several maternal relatives (Figure 1). FF-ERG demonstrated significantly reduced cone response and slightly reduced rod response, suggesting a cone-rod dystrophy (CRD; Figure 1). However, further questioning of the family revealed that three additional siblings were affected by early-onset RP, but without PCD (Figure 1). His family history was positive for nyctalopia in three maternal male relatives, and a single kidney in his mother's grandfather and his brother (suggestive of an XL inheritance pattern for both traits; Figure 1).