Total callosotomy ameliorates epileptic activity and improves cognitive function in a patient with Miller-Dieker syndrome

Miller-Dieker syndrome (MDS) is characterized by facial abnormalities and lissencephaly and is caused by a microdeletion in the region containing the LIS1 gene at chromosome 17p13.3. We report a case in which postnatal neuroimaging revealed severe lissencephaly. A 9-month-old boy presented with infantile spasms syndrome. Because of the refractory course of seizures and continued poor vitality, total corpus callosotomy was performed at 28 months of age. Intraoperative electroencephalogram (EEG) showed that the bilateral synchronous epileptiform discharges disappeared immediately after the disconnection. Postoperatively, the epileptic spasms (ES) in clusters disappeared, and single ES followed by focal seizures became the main symptom. The patient smiled more and became more responsive to stimuli. Postoperative scalp interictal EEG showed desynchronized multifocal spike and wave discharges with a marked decrease in the bilateral synchronous spike and wave discharges. Our findings suggest that the corpus callosum is involved in the mechanism ES in clusters in MDS-associated lissencephaly, and total callosotomy could be a therapeutic option.

Further expansion and confirmation of phenotype in rare loss of YWHAE gene distinct from Miller-Dieker syndrome

Deletion of 17p13.3 has varying degrees of severity on brain development based on precise location and size of the deletion. The most severe phenotype is Miller-Dieker syndrome (MDS) which is characterized by lissencephaly, dysmorphic facial features, growth failure, developmental disability, and often early death. Haploinsufficiency of PAFAH1B1 is responsible for the characteristic lissencephaly in MDS. The precise role of YWHAE haploinsufficiency in MDS is unclear. Case reports are beginning to elucidate the phenotypes of individuals with 17p13.3 deletions that have deletion of YWHAE but do not include deletion of PAFAH1B1. Through our clinical genetics practice, we identified four individuals with 17p13.3 deletion that include YWHAE but not PAFAH1B1. These patients have a similar phenotype of dysmorphic facial features, developmental delay, and leukoencephalopathy. In a review of the literature, we identified 19 patients with 17p13.3 microdeletion sparing PAFAH1B1 but deleting YWHAE. Haploinsufficiency of YWHAE is associated with brain abnormalities including cystic changes. These individuals have high frequency of epilepsy, intellectual disability, and dysmorphic facial features including prominent forehead, epicanthal folds, and broad nasal root. We conclude that deletion of 17p13.3 excluding PAFAH1B1 but including YWHAE is associated with a consistent phenotype and should be considered a distinct condition from MDS.

Prenatal diagnosis of Miller-Dieker syndrome/PAFAH1B1-related lissencephaly: Ultrasonography and genetically investigative results

OBJECTIVE

To present the experience on prenatal diagnosis of Miller-Dieker syndrome (MDS)/PAFAH1B1-related lissencephaly to further determine fetal phenotypes of this syndrome.

STUDY DESIGN

This was a retrospective study of ten pregnancies with fetal MDS/PAFAH1B1-related lissencephaly identified by chromosomal microarray (CMA)/exome sequencing (ES). Clinical and laboratory data were collected and reviewed for these cases, including maternal demographics, prenatal sonographic findings, CMA or ES results and pregnancy outcomes.

RESULTS

Two cases were diagnosed in the first trimester because of an increased nuchal translucency. The remaining eight cases were identified at late gestation, including four in the second trimester because of fetal cardiac anomalies or ventriculomegaly, and four in the third trimester because of ventriculomegaly. CMA revealed 17p13.3 deletions in nine cases, and ES detected a de novo PAFAH1B1 missense mutation in one case.

CONCLUSION

The prenatal presentation of MDS/PAFAH1B1-related lissencephaly depended on the gestational age when the diagnosis was made. Mild ventriculomegaly was the most common prenatal sonographic sign identified in cases of MDS/PAFAH1B1-related lissencephaly. It is important that fetal MRI and invasive testing with CMA should be considered in fetuses with apparently 'isolated' mild ventriculomegaly.

Central-part laryngectomy after laryngotracheal separation to manage pharyngocutaneous fistula: A case report and retrospective analysis of 12 cases

A 15-year-old girl presented with a 3-year-history of continuous outflow of saliva from a pharyngocutaneous fistula, located at 5 mm superior to her tracheal stoma. She was diagnosed with Miller-Dieker syndrome at birth. At 2 years of age, pediatric surgeons at our institution carried out laryngotracheal separation to prevent aspiration pneumonia. At the age of 12 years, she developed continuous saliva discharge from the fistula. We performed central-part laryngectomy and resection of the pharyngocutaneous fistula, which relieved her from the continuous saliva discharge. Central-part laryngectomy is less invasive and easier to perform than total laryngectomy. We hereby present a case and retrospective analysis of 12 patients, who underwent central-part laryngectomy.

Prenatal diagnosis of Miller-Dieker syndrome by chromosomal microarray

OBJECTIVE

To assess the experience on prenatal diagnosis of Miller-Dieker syndrome (MDS) to further delineate the fetal presentation of this syndrome.

METHODS

This was a retrospective study. Fetal MDS was diagnosed prenatally by chromosomal microarray (CMA). Clinical data were reviewed for these cases, including maternal characteristics, indications for prenatal diagnosis, sonographic findings, CMA results, and pregnancy outcomes.

RESULTS

Four cases were diagnosis as MDS by CMA. The most common sonographic features were ventriculomegaly (3/4) and polyhydramnios (2/4). Deletion sizes ranged from 1.5 to 5.4 Mb. All microdeletions were located at the MDS critical region and showed haploinsufficiency of the YWHAE, CRK, and PAFAH1B1. All patients chose to terminate the pregnancy. Parental chromosome analysis were preformed in three cases and demonstrated that two cases were de novo and one case was caused by inherited derivative chromosomes from parental balanced translocations.

CONCLUSION

The most common prenatal ultrasound findings of MDS were ventriculomegaly and polyhydramnios. CMA can improve diagnostic precision for detecting MDS.

Rare Concurrence of Two Congenital Disorders: Miller-Dieker Syndrome and T-Cell Lymphopenia

Miller-Dieker syndrome (MDS; OMIM 247200) is a rare contiguous gene deletion syndrome associated with lissencephaly and characteristic facial dysmorphism. T-cell lymphopenia is an immunodeficiency disorder which can be early detected by newborn blood screening, and all live vaccines should be avoided. We report a 2.32-Mb microdeletion at chromosome 17p13.3p13.2 and T-cell lymphopenia in a 6-month-old male infant with MDS. This is, to our knowledge, the first description of these 2 conditions co-occurring in the same patient.

Miller-Dieker Syndrome due to a 5.5-Mb 17p Deletion in a 17;Y Pseudodicentric Chromosome

Miller-Dieker syndrome (MDS) is a contiguous gene deletion syndrome in which almost all patients present de novo 17p13.3 deletions. We report on a male infant with MDS and an unusual unbalanced translocation involving chromosomes Y and 17 that resulted in a large 5.5-Mb 17pterp13.2 deletion and a karyotype with 45 chromosomes. Apart from the deletion of the MDS critical region, the deletion of additional distal genes seemed to have no major influence on the patient's phenotype, since he did not show any unusual clinical findings that are not commonly described in MDS patients.

A Case of Concurrent Miller-Dieker Syndrome (17p13.3 Deletion) and 22q11.2 Deletion Syndrome

Features of Miller-Dieker syndrome (MDS, 17p13.3 deletion syndrome, LIS1-associated lissencephaly) include classic lissencephaly, microcephaly, cardiac malformations, growth restriction, and characteristic facial changes. Individuals with 22q11.2 deletion syndrome (DiGeorge syndrome or velocardiofacial syndrome) are known to have congenital cardiac malformations (in particular conotruncal defects), palatal abnormalities (especially velopharyngeal insufficiency), hypocalcemia, immune deficiency, learning disabilities, and characteristic facial features. This case report describes phenotypic characteristics of a patient with extremely rare instance of having both MDS and 22q11.2 deletion syndrome that is unique in the medical literature. Prognosis in this concurrent phenotype is poor with our patient suffering from several malformations seen in both conditions and expiring in the neonatal period.