Angelman Syndrome Caused by Chromosomal Rearrangements: A Case Report of 46,XX,+der(13)t(13;15)(q14.1;q12)mat,-15 with an Atypical Phenotype and Review of the Literature.

Less than 1% of the cases with Angelman syndrome (AS) are caused by chromosomal rearrangements. This category of AS is not well defined and may manifest atypical phenotypes. Here, we report a girl with AS due to der(13)t(13;15)(q14.1;q12)mat. SNP array detected the precise deletion/duplication points and the parental origin of the 15q deletion. Multicolor FISH confirmed a balanced translocation t(13;15)(q14.1;q12) in her mother. Her facial appearance showed some features of dup(13)(pter→q14). Also, she lacked the most characteristic and unique behavioral symptoms of AS, i.e., frequent laughter, happy demeanor, and easy excitability. A review of the literature indicated that AS cases caused by chromosomal rearrangements can be classified into 2 major categories and 4 groups. The first category is paternal uniparental disomy 15, which is subdivided into isodisomy by de novo rob(15;15) and heterodisomy caused by paternal translocation. The second category is the deletion of the AS locus due to maternal reciprocal translocation, which is subdivided into 2 groups associated with partial monosomy by 3:1 segregation and partial trisomy by adjacent-2 segregation. Classification into these categories facilitates the understanding of the mechanisms of chromosomal rearrangements and helps in accurate diagnosis and genetic counseling of these rare forms of AS.

A 16q12.2q21 deletion identified in a patient with developmental delay, epilepsy, short stature, and distinctive features.

Interstitial deletions of the 16q centromeric region are rarely reported. A microdeletion of the 16q12.2q21 region was identified in a patient with intellectual disability, epilepsy, short stature, and distinctive features; including up-slanting palpebral fissures, hypertelorism, epicanthic folds, anteverted nares, simple philtrum, thin upper lip vermilion, high arched palate, posteriorly rotated ears, and overlapping toes in his right foot. Although the deleted region includes the genes responsible for neurological impairments (GNOA1, GPR56, KATNB1, and BBS2), haploinsufficiency of these genes would not be associated with the patient's phenotype. When NDRG4, present in the deleted region, was knocked out in mice, these mice exhibited spatial learning deficits. Thus, we hypothesize that this gene could be a potential candidate underlying the neurological observations of the patient. Because RSPRY1 was been discovered as the cause of progressive skeletal dysplasia, a loss of this gene might explain the skeletal defects observed in the patient.

Hemiconvulsion-hemiplegia-epilepsy syndrome associated with CACNA1A S218L mutation.

Hemiconvulsion-hemiplegia-epilepsy syndrome involves sudden and prolonged unilateral seizures, followed by transient or permanent hemiplegia and epilepsy during infancy or early childhood. Some patients with familial hemiplegic migraine and demonstrating the S218L mutation in CACNA1A experience severe attacks with unilateral cerebral edema after trivial head trauma. We report on a 5-year-old Japanese girl presenting with hemiconvulsion-hemiplegia-epilepsy syndrome after infection with parvovirus B19. Magnetic resonance imaging performed 2 days after admission revealed cerebellar atrophy and marked hyperintensity in the left hemisphere on T(2)-weighted and diffusion-weighted imaging. Magnetic resonance angiography performed 7 days after admission demonstrated obliteration of the left proximal middle cerebral artery in the acute phase. However, this finding was not evident on brain angiography performed 25 hours after magnetic resonance angiography. Genetic analysis of familial hemiplegic migraine revealed a heterozygous S218L mutation in CACNA1A. Taken together, these results suggest that vasospasms of cerebral vascular smooth muscle, with possible cortical spreading depression, may have caused the hemiconvulsions and hemiplegia in the left hemisphere. This case report is the first, to the best of our knowledge, to associate CACNA1A with hemiconvulsion-hemiplegia-epilepsy syndrome and familial hemiplegic migraine, and to suggest that similar pathogenic mechanisms may underlie these two disorders.

Sterile pyuria in patients with Kawasaki disease originates from both the urethra and the kidney.

To identify the origin of urinary leukocytes in Kawasaki disease (KD) patients with pyuria, we prospectively studied clinical and laboratory findings of 23 KD patients. Patients were divided into three groups: patients without pyuria, patients with pyuria in both voided urine and bladder urine obtained by transurethral catheterization (bladder pyuria) and patients with pyuria only in voided urine (urethral pyuria). Pyuria in voided urine was found in ten of 23 KD patients (43.5%), with subsequent urine cultures proving sterile. Five out of ten patients with pyuria in voided urine also exhibited pyuria in bladder urine, whilst the remaining patients did not have pyuria in bladder urine. Urinary protein levels were higher in patients with bladder pyuria and in patients with urethral pyuria than in patients without pyuria. Urinary beta2-microglobulin concentrations and serum blood urea nitrogen (BUN) and creatinine levels were higher in patients with bladder pyuria than in patients with urethral pyuria or in patients without pyuria, although the serum BUN and creatinine levels of patients with bladder pyuria were within the normal ranges. These results suggest that some patients with KD develop sterile pyuria that originates from the urethra and/or the kidney as a result of mild and subclinical renal injury.

Hyponatremia in Kawasaki disease.

Although hyponatremia frequently occurs in Kawasaki disease (KD), the clinical characteristics of KD patients with hyponatremia and the pathogenesis of hyponatremia in KD remain unknown. The aims of this study were to define the clinical characteristics of KD patients with hyponatremia (serum sodium <135 mEq/l) and to determine the factors associated with its development. One hundred and fourteen patients with KD were included in this study. Fifty-one patients (44.7%) had hyponatremia. Coronary artery lesions and dehydration were significantly more common in patients with hyponatremia. The duration of fever was significantly longer in patients with hyponatremia. Pyuria and hematuria were present significantly more often in patients with hyponatremia. The serum concentrations of potassium, chloride and total cholesterol were significantly lower in patients with hyponatremia. Serum C-reactive protein and alanine aminotransferase were significantly higher in patients with hyponatremia. Some patients with pyuria and hyponatremia exhibited increased excretion of urinary tubular epithelial cells and urinary casts. There was no difference in the incidence of diarrhea between patients with hyponatremia and patients without hyponatremia. These results indicate that hyponatremia in KD occurs in patients exhibiting severe inflammation. Further studies will be necessary to confirm the pathogenic mechanisms of hyponatremia in patients with KD.