Compound heterozygous ADAMTS9 variants in Joubert syndrome-related disorders without renal manifestation.

BACKGROUND: Ciliopathies are the outcomes of defects of primary cilia structures and functions which cause multisystemic developmental disorders, such as polycystic kidney disease, nephronophthisis, retinitis pigmentosa, Joubert syndrome (JS), and JS-related disorders (JSRD) with additional organ involvement including oral-facial-digital syndrome and so on. They often share common and unexpected phenotypic features. CASE PRESENTATION: We report a 4-year-old-boy case with compound heterozygous variants of ADAMTS9. Unlike the cases with ADAMTS9 variants in the previous report, which identified that homozygous variants of ADAMTS9 were responsible for nephronophthisis-related ciliopathies in two cases, the current case did not have nephronophthisis nor renal dysfunction, and his clinical features, such as oculomotor apraxia, hypotonia, developmental delay, bifid tongue, and mild hypoplasia of cerebellar vermis indicated JSRD. CONCLUSIONS: The case suggested a possible association between the clinical presentation of JSRD and ADAMTS9-related disease, and it shows a wide spectrum of ADAMTS9 phenotype.

A female patient with a hot spot mutation of PRRT2 gene suffering from several types of epileptic seizures in infancy.

Benign familial infantile epilepsy (BFIE) is characterized by non-febrile focal seizures, which sometimes evolve to secondarily generalized seizures and are usually resolved in the second year. Proline-rich transmembrane protein 2 (PRRT2) is confirmed as the major cause of BFIE, familial paroxysmal kinesigeneic dystonia (PKD) and infantile convulsions and choreoathetosis (ICCA) syndrome. We examined a female patient with a hot spot mutation of PRRT2 gene. She had recurrent tonic seizures when she was three months old. The seizures were controlled by several kinds of anticonvulsants. Then, she had several times of focal seizures daily at nine months old. However, the seizures were stopped by small amounts of carbamazepine. Later, when she was two years old, she experienced frequent motor seizures characterized by truncal flexion and swaying the body with partially disturbed consciousness. Her father also had the same PRRT2 gene mutation and non-febrile seizures in infancy. The patient had mild to moderate mental retardation, whereas her father was mentally normal. Therefore, the patient revealed a quiet different phenotype from that of her father as a carrier of the same PRRT2 gene mutation. We speculate that the PRRT2 mutation had caused the BFIE-like seizures both in the patient and her father, whereas other unknown genetic factors specific for the patient might be associated with the atypical seizures observed only in her.

Anatomical characterization of athetotic and spastic cerebral palsy using an atlas-based analysis.

PURPOSE: To analyze diffusion tensor imaging (DTI) in two types of cerebral palsy (CP): the athetotic-type and the spastic-type, using an atlas-based anatomical analysis of the entire brain, and to investigate whether these images have unique anatomical characteristics that can support functional diagnoses. MATERIALS AND METHODS: We retrospectively analyzed the DTI of seven children with athetotic-type, 11 children with spastic-type, and 20 healthy control children, all age-matched. The severity of motor dysfunction was evaluated with the Gross Motor Function Classification System (GMFCS). The images were normalized using a linear transformation, followed by large deformation diffeomorphic metric mapping. For 205 parcellated brain areas, the volume, fractional anisotropy, and mean diffusivity were measured. Principal component analysis (PCA) was performed for the Z-scores of these parameters. RESULTS: The GMFCS scores in athetotic-type were significantly higher than those in spastic-type (P < 0.001). PCA extracted anatomical components that comprised the two types of CP, as well as the severity of motor dysfunction. In the athetotic group, the abnormalities were more severe than in the spastic group. In the spastic group, significant changes were concentrated in the lateral ventricle and periventricular structures. CONCLUSION: Our results quantitatively delineated anatomical characteristics that reflected the functional findings in two types of CP.