Usefulness of high-resolution comparative genomic hybridization (CGH) for detecting and characterizing constitutional chromosome abnormalities

Comparative genomic hybridization (CGH) is a technique for detection of chromosomal imbalances in a genomic DNA sample. We here report the application of the recently developed method of high-resolution CGH on DNA samples from 66 children having various degrees of delayed psychomotor development with or without clear dysmorphic features and congenital malformations. In 5 of 50 patients with apparently normal karyotypes, a deletion or duplication was revealed by CGH. Only one of these cases had a subtelomeric rearrangement. In one of seven cases with a de novo apparently balanced translocation, deletions were found. In all nine cases where the origin of a marker chromosome or additional chromosomal material was difficult to determine, CGH gave a precise identification. The following findings were from cases having a deletion or duplication as the sole chromosomal imbalance; dup(2)(p16p21), del(4)(q21q21), del(6)(q14q15), del(6)(p12p12), dup(6)(q24qter), and dup(15)(q11q13). One case had dup(9)(p11pter) combined with a very small subtelomeric deletion on 6q. In our hands, CGH is highly useful not only for identifying known chromosomal imbalances, but also for finding elusive deletions or duplications in the large group of children with developmental delay with or without congenital abnormalities. In such cases, the diagnostic yield of CGH appears to be higher than what has been reported from subtelomeric FISH screening.     

Dominant ARL3-related retinitis pigmentosa

Purpose: To clinically and genetically characterise a second family with dominant ARL3-related retinitis pigmentosa due to a specific ARL3 missense variant, p.(Tyr90Cys).

Methods: Clinical examination included optical coherence tomography, electroretinography, and ultra-wide field retinal imaging with autofluorescence. Retrospective data were collected from the registry of inherited retinal diseases at Oslo university hospital. DNA was analysed by whole-exome sequencing and Sanger sequencing. The ARL3 missense variant was visualized in a 3D-protein structure.

Results: The phenotype was non-syndromic retinitis pigmentosa with cataract associated with early onset of decreased central vision and central retinal thinning. Sanger sequencing confirmed the presence of a de novo ARL3 missense variant p.(Tyr90Cys) in the index patient and his affected son. We did not find any other cases with rare ARL3 variants in a cohort of 431 patients with retinitis pigmentosa-like disease. By visualizing Tyr90 in the 3D protein structure, it seems to play an important role in packing of the α/β structure of ADP-ribosylation factor-like 3 (ARL3). When changing Tyr90 to cysteine, we observe a loss of interactions in the core of the α/β structure that is likely to affect folding and stability of ARL3.

Conclusion: Our study confirms that the ARL3 missense variant p.(Tyr90Cys) causes retinitis pigmentosa. In 2016, Strom et al. reported the exact same variant in a mother and two children with RP, labelled ?RP83 in the OMIM database. Now the questionmark can be removed, and ARL3 should be added to the list of genes that may cause non-syndromic dominant retinitis pigmentosa.     

Focal and segmental glomerular sclerosis (FSGS) in a man and a woman with Fabry's disease

We describe a man and a woman with Fabry's disease. Renal biopsies showed late and early stages respectively of focal and segmental glomerulosclerosis (FSGS) and vascular changes. Clinically the hemizygous patient had advanced renal disease with nephrotic range proteinuria and serum creatinine 122 micromol/l. The female carrier had minimal albuminuria, borderline GFR with a normal serum creatinine, acroparesthesias, moderate fatigue, tinnitus and headache accompanied by ischemic cerebral lesions. Enzyme replacement therapy (ERT) was initiated according to our Fabry protocol, partly due to the renal morphologic findings. We conclude that FSGS and vascular changes may be an early morphologic finding in Fabry's disease, even in patients with subtle albuminuria. The potential role of FSGS as a marker of progressive renal disease in some Fabry patients is discussed. As FSGS and vascular changes obviously may exist across a wide range of clinical presentations and have potential prognostic implications, we suggest that a renal biopsy should be performed prior to enzyme replacement therapy in all adult Fabry patients with proteinuria of various levels. Efforts should be made to develop a scoring system to evaluate potential histologic markers. Protocol biopsies may have therapeutic implications and may provide valuable information in the evaluation of start and dosing of ERT.     

Absent CNKSR2 causes seizures and intellectual,attention, and language deficits

Synaptic function is central to brain function. Understanding the synapse is aided by studies of patients lacking individual synaptic proteins. Common neurological diseases are genetically complex. Their understanding is likewise simplified by studies of less common monogenic forms. We detail the disease caused by absence of the synaptic protein CNKSR2 in 8 patients ranging from 6 to 62 years old. The disease is characterized by intellectual disability, attention problems, and abrupt lifelong language loss following a brief early childhood epilepsy with continuous spike‐waves in sleep. This study describes the phenotype of CNKSR2 deficiency and its involvement in systems underlying common neurological disorders. Ann Neurol 2014;76:758–764     

Further delineation of an entity caused by CREBBP and EP300 mutations but not resembling Rubinstein–Taybi syndrome

In 2016, we described that missense variants in parts of exons 30 and 31 of CREBBP can cause a phenotype that differs from Rubinstein–Taybi syndrome (RSTS). Here we report on another 11 patients with variants in this region of CREBBP (between bp 5,128 and 5,614) and two with variants in the homologous region of EP300. None of the patients show characteristics typical for RSTS. The variants were detected by exome sequencing using a panel for intellectual disability in all but one individual, in whom Sanger sequencing was performed upon clinical recognition of the entity. The main characteristics of the patients are developmental delay (90%), autistic behavior (65%), short stature (42%), and microcephaly (43%). Medical problems include feeding problems (75%), vision (50%), and hearing (54%) impairments, recurrent upper airway infections (42%), and epilepsy (21%). Major malformations are less common except for cryptorchidism (46% of males), and cerebral anomalies (70%). Individuals with variants between bp 5,595 and 5,614 of CREBBP show a specific phenotype (ptosis, telecanthi, short and upslanted palpebral fissures, depressed nasal ridge, short nose, anteverted nares, short columella, and long philtrum). 3D face shape demonstrated resemblance to individuals with a duplication of 16p13.3 (the region that includes CREBBP), possibly indicating a gain of function. The other affected individuals show a less specific phenotype. We conclude that there is now more firm evidence that variants in these specific regions of CREBBP and EP300 result in a phenotype that differs from RSTS, and that this phenotype may be heterogeneous.

     

The impact of roles on the evaluation of administrative effectiveness

This study finds that judgments about the effectiveness of community mental health center directors are affected by the roles that the judges have in relation to the centers. CMHC executives were found to be very similar to their clinical colleagues and different from governing board members in the importance they placed on those things that characterize the effective CMHC administrator.Ian Macindoe, Ph.D, MHA is with the Foundation for Health Care Evaluation, Suite 400, 20 Washington Ave. S., Minneapolis, MN 55401. Reprint requests may be addressed to him there. Donald R. Houge, Ph.D. is Assistant Professor in the Department of Family Practice and Community Health, Medical School, University of Minnesota, Minneapolis, MN 55455.     

Monosomy 8 rescue gave cells with a normal karyotype in a mildly affected man with 46,XY,r(8) mosaicism

The psychomotor and somatic development from early childhood into adult life is described in a man with 46,XY,r(8)/46,XY mosaicism. The ring chromosome 8 appeared to be of normal length on G-banding, but terminal deletions on 8q and 8p were detected with FISH and CGH. By STR marker analysis the 8p deletion proved to be quite large, at least 6.74 Mb, while the 8q deletion was small, around 2.5 Mb. The haplotype analysis also demonstrated that the r(8) originated from a maternal chromosome 8, and that cells with normal male karyotype resulted from monosomy 8 rescue after loss of the ring 8, i.e. a mitotic duplication of the paternal chromosome 8. The patient has a mild phenotype with no malformations and mild mental retardation, also compared to other ring chromosome 8 patients. His clinical condition has remained stable for the last 20 years.     

Deleterious de novo variants of X‐linked ZC4H2 in females cause a variable phenotype with neurogenic arthrogryposis multiplex congenita

Pathogenic variants in the X‐linked gene ZC4H2, which encodes a zinc‐finger protein, cause an infrequently described syndromic form of arthrogryposis multiplex congenita (AMC) with central and peripheral nervous system involvement. We present genetic and detailed phenotypic information on 23 newly identified families and simplex cases that include 19 affected females from 18 families and 14 affected males from nine families. Of note, the 15 females with deleterious de novo ZC4H2 variants presented with phenotypes ranging from mild to severe, and their clinical features overlapped with those seen in affected males. By contrast, of the nine carrier females with inherited ZC4H2 missense variants that were deleterious in affected male relatives, four were symptomatic. We also compared clinical phenotypes with previously published cases of both sexes and provide an overview on 48 males and 57 females from 42 families. The spectrum of ZC4H2 defects comprises novel and recurrent mostly inherited missense variants in affected males, and de novo splicing, frameshift, nonsense, and partial ZC4H2 deletions in affected females. Pathogenicity of two newly identified missense variants was further supported by studies in zebrafish. We propose ZC4H2 as a good candidate for early genetic testing of males and females with a clinical suspicion of fetal hypo‐/akinesia and/or (neurogenic) AMC.     

Exercise Self-Efficacy and patient global assessment were associated with 6-min walk test distance in persons with rheumatoid arthritis

Introduction

Low functional capacity is related to future loss of daily function and cardiovascular events. The present study explored the associations of patient-reported outcome measures (PROMs) and disease-specific measures with functional capacity as measured by the 6-min walk test (6MWT) in persons with rheumatoid arthritis (RA).

Methods

Seventy-nine participants from rheumatology outpatient clinics were included. The distance walked during the 6MWT (6MWD) was the dependent variable in multivariable regression analyses. Model 1 included the independent variables sex, age (in tertiles to improve model fit), and body mass index (BMI). Building on Model 1, Model 2 added smoking, patient global assessment (PGA), Exercise Self-Efficacy, Hospital Anxiety and Depression Scale’s Depression score, and Cohen’s Perceived Stress Scale score, whereas Model 3 added smoking, disease duration, present use of glucocorticosteroids, seropositivity, Disease Activity Score 28—C-Reactive Protein (DAS28-CRP), and a comorbidity variable.

Results

Median age was 65 years, 76% were female, and median 6MWD was 493 m. In Model 1, BMI and age were significantly associated with the 6MWD (R² = 0.42). In Model 2, PGA and Exercise Self-Efficacy were also significantly associated with the 6MWD, with standardized regression coefficients of − 0.21 (p = 0.03) and 0.26 (p = 0.004) respectively (R² = 0.54). The RA-specific variables in Model 3 were not significantly associated with the 6MWD (R² = 0.49).

Conclusion

The PROMs PGA and Exercise Self-Efficacy were significantly associated with functional capacity as measured by the 6MWT in persons with RA, whereas disease-specific measures such as DAS28-CRP and disease duration were not.