A recurrent single-amino acid deletion (p.Glu500del) in the head domain of ß-cardiac myosin in two unrelated boys presenting with polyhydramnios, congenital axial stiffness and skeletal myopathy

BACKGROUND

Alterations in the MYH7 gene can cause cardiac and skeletal myopathies. MYH7-related skeletal myopathies are extremely rare, and the vast majority of causal variants in the MYH7 gene are predicted to alter the rod domain of the of ß-cardiac myosin molecule, resulting in distal muscle weakness as the predominant manifestation. Here we describe two unrelated patients harboring an in-frame deletion in the MYH7 gene that is predicted to result in deletion of a single amino acid (p.Glu500del) in the head domain of ß-cardiac myosin. Both patients display an unusual skeletal myopathy phenotype with congenital axial stiffness and muscular hypertonus, but no cardiac involvement.

RESULTS

Clinical data, MRI results and histopathological data were collected retrospectively in two unrelated boys (9 and 3.5 years old). Exome sequencing uncovered the same 3-bp in-frame deletion in exon 15 (c.1498_1500delGAG) of the MYH7 gene of both patients, a mutation which deletes a highly conserved glutamate residue (p.Glu500del) in the relay loop of the head domain of the ß-cardiac myosin heavy chain. The mutation occurred de novo in one patient, whereas mosaicism was detected in blood of the father of the second patient. Both boys presented with an unusual phenotype of prenatal polyhydramnios, congenital axial stiffness and muscular hypertonus. In one patient the phenotype evolved into an axial/proximal skeletal myopathy without distal involvement or cardiomyopathy, whereas the other patient exhibited predominantly stiffness and respiratory involvement. We review and compare all patients described in the literature who possess a variant predicted to alter the p.Glu500 residue in the ß-cardiac myosin head domain, and we provide in-silico analyses of potential effects on polypeptide function.

CONCLUSION

The data presented here expand the phenotypic spectrum of mutations in the MYH7 gene and have implications for future diagnostics and therapeutic approaches.

Multidisziplinäre Diagnostik von Entwicklungsstörungen: Grundlage der „personalized precision medicine“

Das Spektrum der Entwicklungsstörungen gehört zum Alltag des Facharztes für Kinder- und Jugendmedizin. Durch den zunehmenden Einsatz von „Next-generation sequencing“-Methoden in den letzten 10 Jahren werden die genetischen Hintergründe besser verstanden. Hiermit eröffnen sich Möglichkeiten in der Routinediagnostik und auch für pathomechanismusbasierte individuelle Therapieansätze („personalized precision medicine“). Dieser Beitrag beschreibt die patientenzentrierte Einbettung einer multidisziplinären Tagesklinik („Murmeltiersprechstunde“) zu zeit- und ressourcensparender Diagnostik und Behandlung von Entwicklungsstörungen. Bei 43 an der Murmeltiersprechstunde teilnehmenden Kindern (Durchschnittsalter 4,9 Jahre) mit einer Entwicklungsstörung konnte in 24 Fällen (56 %) eine pathogene Variante in einem bereits bekannten Krankheitsgen, in 4 weiteren Fällen (12 %) in einem Kandidatengen gefunden werden und somit eine Diagnose gestellt werden. Hierdurch konnte in 6 Fällen (14 %) eine pathomechanismusbasierte Therapie erfolgreich eingeleitet werden. Die durchschnittliche Dauer zwischen der Aufnahme in der Tagesklinik und der Befundmitteilung betrug 6 Monate. Die Murmeltiersprechstunde zeigt, wie „personalized precision medicine“ in den Alltag einer Kinderklinik eingebaut werden kann und direkten Einfluss auf die Behandlung hat.

Leigh disease with brainstem involvement in complex I deficiency due to assembly factor NDUFAF2 defect

Mitochondrial NADH: ubiquinone oxidoreductase (complex I) deficiency accounts for most defects in mitochondrial oxidative phosphorylation. Pathogenic mutations have been described in all 7 mitochondrial and 12 of the 38 nuclear encoded subunits as well as in assembly factors by interfering with the building of the mature enzyme complex within the inner mitochondrial membrane. We now describe a male patient with a novel homozygous stop mutation in the NDUFAF2 gene. The boy presented with severe apnoea and nystagmus. MRI showed brainstem lesions without involvement of basal ganglia and thalamus, plasma lactate was normal or close to normal. He died after a fulminate course within 2 months after the first crisis. Neuropathology verified Leigh disease. We give a synopsis with other reported patients. Within the clinical spectrum of Leigh disease, patients with mutations in NDUFAF2 present with a distinct clinical pattern with predominantly brainstem involvement on MRI. The diagnosis should not be missed in spite of the normal lactate and lack of thalamus and basal ganglia changes on brain MRI.

Pontine tegmental cap dysplasia: the severe end of the clinical spectrum

Pontine tegmental cap dysplasia (PTCD) is a newly described hindbrain malformation with distinct neuroradiological findings. Only 12 cases of PTCD have been described so far, all sporadic. We report 2 further patients. Both children presented after birth with significant feeding problems due to impaired mouth opening (previously not reported) and sucking difficulties. Facial, cochlear, and glossopharyngeal nerves were involved resulting in bilateral sensory deafness and a significant swallowing disorder requiring a gastrostomy. In one patient the trigeminal sensory nerve was also involved causing severe bilateral corneal clouding with impaired vision. Both patients showed only minimal developmental progress since birth and had no speech production. Furthermore, they had vertebral and rib anomalies. The patients died at the age of 15 and 32 months, respectively, due to intercurrent infections. The majority of patients reported previously were affected less severely. The presented patients may represent the severe end of the spectrum.

Loss of Apaf-1 expression and resistance to hypoxia-induced apoptosis in cervical cancer

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Background: Clinical observations suggest that intratumoral hypoxia may increase the aggressiveness of tumors through clonal selection of cancer cells that have lost their apoptotic potential. We have shown previously that patients with hypoxic cervical cancers displaying a low apoptosis rate had a significantly worse prognosis compared to all other patients. The aim of this study, therefore, was to investigate the expression of the proapoptotic protein Apaf-1 in cervical cancers and to analyze its relation to intratumoral hypoxia and apoptosis. Methods: 56 patients with cervical cancer (FIGO stage IB to IV) were subjected to pretherapeutical intratumoral pO2 measurement with the Eppendorf electrode after informed written consent was given by each patient. The study was approved by the Ethics Committee of the University of Leipzig. Cervical cancer tissue from these patients was taken by needle core biopsy and analyzed by TUNEL assays as well as by immunohistochemistry with an anti-Apaf-1-antibody. For statistical analysis, Fisher’s exact test was used. Results: Apaf-1 was expressed in 86% of cervical cancers. The median apoptosis rate was 1.0% (range: 0.3– 3.4%). There was no direct correlation between Apaf-1 expression and intratumoral hypoxia. However, in the group of hypoxic cervical cancers (pO2 <10 mmHg) with a low apoptosis rate (<1.0%), 43.8 % (95% CI: 19.8–70.1%) of tumors showed a negative Apaf-1 expression compared to only 2.5% (95% CI: 0.06–13.1%) in non-hypoxic cancers and hypoxic cancers with a high apoptosis rate (p = 0.0003, Fisher’s exact test). Conclusions: While Apaf-1 is expressed in the vast majority of cervical cancers, a significant proportion of tumors with low apoptosis rates despite intratumoral hypoxia showed a loss of Apaf-1 expression. This finding suggests a mechanism by which hypoxic cervical cancers acquire resistance to apoptosis.

No significant financial relationships to disclose.

A case of Ohtahara syndrome with olivary-dentate dysplasia and agenesis of mamillary bodies

We report a patient with early infantile epileptic encephalopathy (EIEE) with suppression-burst (Ohtahara syndrome) associated with olivary-dentate dysplasia and agenesis of mamillary bodies is reported. Although those with Ohtahara syndrome are a heterogeneous group, virtually all reported cases are secondary to neuronal migrational disorders, sometimes only identified by detailed neuropathologic examination, as in this case report, which describes mamillary body agenesis as a not-yet-recognized anomaly associated with Ohtahara syndrome. All children with Ohtahara syndrome should have high-resolution magnetic resonance imaging (MRI) and detailed postmortem neuropathologic examinations.

MRI and proton spectroscopy in Lowe syndrome

The oculocerebrorenal syndrome of Lowe (OCRL) is an X-linked disorder characterized by major abnormalities of eyes, nervous system, and kidneys. We report two patients with typical intracranial lesions on MRI. The proton spectroscopy study of the periventricular white matter showed a moderate elevation of the signal at 3.56 ppm in the patient with cystic lesions. This resonance is usually assigned to myo-inositol and interpreted as a glial marker. In our patient it could also represent a true accumulation inside the cysts of phosphatidylinositol 4,5-biphosphate which is not degraded in patients with Lowe syndrome.

Tunable femtosecond-pulse generation by an optical parametric oscillator in the saturation regime

We demonstrate the generation of powerful, bandwidth-limited pulses in a KTP optical parametric oscillator synchronously excited by the pulse train of a f lash-lamp-pumped, mode-locked Nd:YLF laser. Operating the optical parametric oscillator a factor of 4 above threshold and optimizing the cavity length yields pulses of 260 +/- 30 fs. The shortening by a factor of 15 relative to the pump is accompanied by extended pulse wings. Tunability of the device is shown in the wavelength range 1.2 -1.6 microm.

Malnutrition among the elderly

Nutrition is a significant determinant of health. Undernutrition presenting as malnutrition is a serious health concern for frail elderly people with many health problems. Understanding the risk factors for malnutrition helps physicians assess and manage the condition. Primary care physicians are in an excellent position to screen, educate, and manage their elderly malnourished patients.

The unexpected relocation of elderly in-patients in response to a threatened strike

A threatened strike by non-professional hospital employees caused a teaching hospital to halve its in-patient numbers. This paper describes this unexpected, involuntary intervention in patient care in the Department of Geriatric Medicine. Fifty-three patients were discharged, 46 patients were transferred for 12 days to another hospital and 29 remained in the department. There was no evidence of important disruption in patient-care nor exacerbation of patient-distress as seen in ratings of patients' social, emotional and physical functioning. It is suggested that important factors in achieving successful unexpected relocation are: selection of patients who are medically stable albeit with significant physical and mental disability; the preparation and participation of patients and staff; and the continuation of patient care by nursing staff familiar to the patients.