Prenatal Diagnosis and Molecular Cytogenetic Analyses of a de novo Deletion on Chromosome 4p16.3p15.33.

Wolf-Hirschhorn syndrome (WHS) (OMIM 194190) is a contiguous gene syndrome with an estimated prevalence of around 1 in 50,000 births. The syndrome is caused by the deletion of a critical region (Wolf-Hirschhorn Syndrome Critical region-WHSCR) on chromosome 4p16.3. Its core features are typical facial gestalt, growth retardation, intellectual disability, developmental delay, and seizures. Prenatal diagnosis of WHS helps clinicians and parents make informed decisions about pregnancy management. In this research, a 31-year-old woman (gravida 1, para 0) underwent amniocentesis at 18 weeks gestation because of the short nasal bone of the fetus on prenatal ultrasound. Chromosomal microarray analysis (CMA) on uncultured amniocytes revealed a de novo 11.36-Mb deletion on chromosome 4p16.3p15.33, spanning from position 40 000 to 11 400 000 (hg19). After genetic counselling and being informed of the unfavorable prognosis, the parents decided to terminate the pregnancy. We provide a detailed description of a de novo 11.36-Mb deletion on chromosome 4p16.3p15.33 (Wolf-Hirschhorn syndrome). CMA has more advantages than karyotype analysis in detecting chromosomal microdeletions/microduplications. A combination of karyotype analysis, CMA, prenatal ultrasound, and genetic counseling is helpful for the prenatal diagnosis of chromosomal deletions/duplications.

Melatonin reverses the oxidative stress and mitochondrial dysfunction caused by LETM1 silencing.

LETM1 is a mitochondrial inner-membrane protein, which is encoded by a gene present in a locus of 4p, which, in turn, is deleted in the Wolf-Hirschhorn Syndrome, and is assumed to be related to its pathogenesis. The cellular damage caused by the deletion is presumably related to oxidative stress. Melatonin has many beneficial roles in protecting mitochondria by scavenging reactive oxygen species, maintaining membrane potential, and improving functions. The aim of this study was to investigate the effects of melatonin administration to LETM1-silenced mouse embryonic fibroblast cells as a cellular model for LETM1 deficiency. We transfected mouse embryonic fibroblast cells with a pair of siRNA against LETM1 and monitored the oxidative stress and mitochondrial functions with or without melatonin addition. MnSOD expression and aconitase activity decreased and oxidized protein levels increased in LETM1-silenced cells. LETM1 suppression did not alter the expression of OXPHOS complexes, but the oxygen consumption rates decreased significantly; however, this change was not related to complex I but instead involved complex IV and complex II. Melatonin supplementation effectively normalized the parameters studied, including the oxygen consumption rate. Our findings identified a novel effect of LETM1 deficiency on cellular respiration via complex II as well as a potential beneficial role of melatonin treatment. On the other hand, these effects may be specific to the cell line used and need to be verified in other cell lines.

Affinity for music in Wolf-Hirschhorn syndrome: two case reports.

BACKGROUND: Wolf-Hirschhorn syndrome is a congenital malformation syndrome resulting from deletion of the short arm of chromosome 4. Individuals with Wolf-Hirschhorn syndrome may have a "Greek warrior helmet" appearance, growth retardation, developmental delay, muscular hypotonia, epilepsy, and difficulty with language including verbal communication. An affinity for music has not previously been reported in these patients. PATIENTS: We describe two patients with Wolf-Hirschhorn syndrome who both have a strong affinity for music. One patient is a 20-year-old woman who likes to listen to music all day and can hum many tunes. The other patient is a 9-year-old girl who is calmed by music and received music therapy, with subsequent improvement in her communication skills (eye contact, joint attention, and vocalizations to request music). CONCLUSIONS: Individuals with Wolf-Hirschhorn syndrome may have a strong affinity for music and may benefit from music therapy. Additional studies are needed to investigate the interest in music in individuals with Wolf-Hirschhorn syndrome.