Psychiatric syndromes in individuals with chromosome 18 abnormalities

18q Deletion Syndrome-Associated Schizophrenia: A Case Report

INTRODUCTION

18q deletion syndrome is a rare genetic disorder characterized by various neurodevelopmental anomalies and medical issues. Although the occurrence of psychosis has been reported in a small number of cases, details regarding the nature of such symptoms and their response to treatment have not been described.

CASE PRESENTATION

We describe a 31-year-old male with a history of speech delays, autistic features, a tethered spinal cord, bilateral vertical talus, subaortic stenosis and aortic regurgitation, recurrent otitis media, mild hearing loss, and hypospadias, who experienced a first episode of psychosis in his late 20s. His psychotic symptoms included auditory hallucinations, various delusions, and disorganization of thought. Although his presentation is atypical in certain ways (e.g., exhibiting highly fluctuant symptoms), he nonetheless meets criteria for schizophrenia. Given his overall clinical picture, chromosomal microarray analysis was completed, which revealed a 19.78 Mb deletion at 18q21.32 from nucleotide 58,226,713 to 78,015,180 (GRCh37). Despite exhibiting a somewhat idiosyncratic response to numerous antipsychotic medications, he eventually achieved partial remission of symptoms with improved insight on relatively low dose oral aripiprazole therapy.

CONCLUSION

This is the first in-depth description of 18q deletion syndrome-associated schizophrenia. While our patient's atypical presentation and idiosyncratic response to treatment may be mediated by his comorbid diagnosis of autism, his unusual psychiatric phenotype may alternatively be directly related to his underlying genetic disorder. The description of additional cases in the future will hopefully help clarify matters further.

Clinical delineation of 18q11-q12 microdeletion: Intellectual disability, speech and behavioral disorders, and conotruncal heart defects

Background

Since the establishment of chromosomal microarrays in clinical practice, many new microdeletion/microduplication syndromes have been identified, including 18q11.2 microdeletion. Chromosome 18q deletion syndrome is commonly classified into distal deletion and a much rarer proximal interstitial deletion spanning the 18q11.2‐q21.1 region.

Methods

We report two new patients and review 27 additional cases in DECIPHER/ClinGen databases and four cases from the literature, with more proximal 18q deletions involving 18q11‐q12 (band 1 only; 17.2–43.5 Mb position) deletion.

Results

Common presentations of 18q11‐q12 deletions include developmental delay/intellectual disability (DD/ID) (82%); speech delay/autism/attention deficit and hyperactivity/other behavioral problems (30%); conotruncal heart defects (15%); and subtle/non‐specific facial dysmorphism. The deletion in four out of five cases with cardiac defect was distal to GATA6, suggesting an alternative mechanism other than haploinsufficiency of GATA6 as an underlying cause of cardiac malformations. Precocious puberty with advanced skeletal age was first observed in one patient, suggesting a unique and expanded phenotype of proximal 18q deletion. When comparing genotype–phenotype correlations from the present study with previous reports, the critical regions for selected phenotypes of 18q11‐q12 deletion syndrome could be narrowed down as follows: 38.8–43.5 Mb for moderate to severe DD/ID, 19.6–24.4 Mb and 26.9–28.6 Mb for conotruncal heart defect.

Conclusion

The detailed clinical delineation of the proximal 18q deletions identified in this study should contribute to better understanding of the genotype–phenotype correlations and better long‐term care of patients with this rare syndrome.

Neuropsychological function in a child with 18p deletion syndrome: a case report

We report the neuropsychological profile of a 4-year-old boy with the rare 18p deletion syndrome. We used a battery of standardized tests to assess his development in intellect, language, visuomotor integration, academic readiness, socialization, and emotional and behavioral health. The results showed borderline intellectual function except for low average nonverbal reasoning skills. He had stronger receptive than expressive language skills, although both were well below his age group. He had impaired visuomotor integration and pre-academic skills such as letter identification. Emotional and behavioral findings indicated mild aggressiveness, anxiety, low frustration tolerance, and executive function weaknesses, especially at home. Interestingly, he showed social strengths, responding to joint attention and sharing enjoyment with his examiner. With its assessment of development in many domains, this case report is among the first to characterize the neuropsychological and psychiatric function of a young child with 18p deletion syndrome. We discuss the implications of our findings for clinical practice.

[Tetrasomy 18p syndrome and hearing loss. An unusual case]

Tetrasomy 18p is a rare chromosomal disease (1:140,000 live births), which affects females and males equally, and might be hereditary or caused by spontaneous changes (de novo formation) within the chromosome. The phenotype results from the presence of a small extra metacentric marker chromosome, an isochromosome 18p. The syndrome is characterized by mild-to-moderate mental retardation, poor language acquisition, seizures, microcephaly, short statue, minor facial dysmorphic features, congenital heart diseases, uro/renal malformations, abnormal muscle tone, spasticity of the lower limbs, and delayed ability to stand and walk. To our knowledge sensorineural hearing loss is described in the literature but has not been described as a typical phenotypic symptom of tetrasomy 18p.In the following report, a boy with tetrasomy 18p is described. In addition to psychomotor retardation with muscular hypotonia and orofacial dismorphysms, bilateral severe hearing loss was diagnosed. Thus, in all infants with known chromosomal aberration, early diagnostic procedures must be performed to unveil sensorineural hearing loss that might be overseen because of mental retardation. In particular, a brainstem-evoked response audiometry (BERA) should be considered for early diagnosis and treatment of possible hearing loss. Furthermore, in all children with developmental delay and dysmorphic features a chromosomal analysis should be initiated.

Prenatally diagnosed submicroscopic familial aberrations at 18p11.32 without phenotypic effect

Background

Recent development of MLPA (Multiplex-Ligation-dependent Probe Amplification, MRC-Holland) and microarray technology allows detection of a wide range of new submicroscopic abnormalities. Publishing new cases and case reviews associated with both clinical abnormalities and a normal phenotype is of great value.

Findings/results

We report on two phenotypically normal foetuses carrying a maternally-inherited interstitial submicroscopic abnormality of chromosome 18p11.32. Both abnormalities were found with the aneuploidy MLPA kit P095 during rapid aneuploidy detection, which was offered along with conventional karyotyping. Foetus 1 and its mother have a 1,7 Mb deletion and foetus 2 and its mother have a 1,9 Mb duplication. In both cases normal babies were born. We used the HumanCytoSNP-12 array of Illumina to visualize the CNVs and map the breakpoints.

Conclusions

We suggest that a CNV at 18p11.32 (528,050-2,337,486) may represent a new benign euchromatic variant.

18q deletion in a cystic fibrosis infant, increased morbidity and challenge for correct treatment choices: a case report

Cystic Fibrosis (CF) is the most frequent recessive disease of Caucasian patients. Association with other diseases or syndromes has previously been reported. Co-morbidity may be a challenge for clinicians, who have to face more severe problems.

We have described a CF infant, F508del homozygote, diagnosed by neonatal screening, who also had a chromosome 18q terminal deletion [del (18)(q22-qter)]. Some clinical features of the 18q deletion: e.g., cardiopathy, gastro-oesophageal reflux and severe muscular hypotonia, worsened the CF clinical picture and his quality of life, with repeated pulmonary exacerbations and failure to thrive in the first six months of life. The treatment strategy was chosen following an accurate multi-disciplinary team study of overlapping chromosome syndrome and CF symptoms. The use of a gastrostomy device for enteral nutrition together with a new device (Ez-PAP) for chest physiotherapy led to normal growth, a notably reduced hospitalization rate and improved quality of life.

This case shows how co-morbidities worsening the clinical course of a "complicated patient" can be faced thanks to unconventional therapies that represent a challenge for clinicians.

Psychiatric characterization of children with genetic causes of hyperandrogenism

OBJECTIVE

Very little is known about the mental health status in children with genetic causes of hyperandrogenism. This study sought to characterize psychiatric morbidity in this group.

DESIGN/METHODS

Children (8-18 years) with the diagnosis of classic congenital adrenal hyperplasia (CAH) or familial male precocious puberty (FMPP) underwent a semi-structured psychiatric interview, the Kiddie Schedule for Affective Disorders and Schizophrenia-Present and Lifetime Version. According to sex and the literature, incidence of identified psychopathology was compared between the two endocrinological groups. We evaluated 72 patients: 54 CAH (21 females) and 18 FMPP.

RESULTS

Twenty-four (44.4%) CAH patients and 10 (55.6%) FMPP patients met the criteria for at least one lifetime psychiatric diagnosis. Attention-deficit hyperactivity disorder (ADHD) was present in 18.2% of CAH males, 44.4% of FMPP males, and one case (4.8%) in CAH females. A high rate of anxiety disorders was also found in all the three groups (17-21%). Relative to females with CAH, the FMPP patients exhibited higher rates of ADHD. Age at diagnosis and the treatment modalities were not associated with psychopathology. Rates of psychiatric disorder, specifically ADHD and anxiety disorders, were higher than in the general population.

CONCLUSION

Although anxiety disorders may occur at an increased rate in children with chronic illness, androgens may contribute to higher risk for psychopathology in pediatric patients with genetic cause of excess androgen. Early diagnosis and treatment of childhood hyperandrogenism is essential for optimal development. The results suggest that assessment for psychiatric disorders should be part of the routine evaluation of these patients.