Ju-Shan Yu

Treacher Collins Syndrome with a de Novo 5-bp Deletion in the TCOF1 Gene

Treacher Collins syndrome (TCS) is an autosomal dominant disorder of craniofacial development with features including malar hypoplasia, micrognathia, microtia, downward slanting palpebral fissures, lower eyelid coloboma, conductive hearing loss, and cleft palate. TCS is caused by mutations in the TCOF1 gene, which encodes the nuclear phosphoprotein treacle. Here, we describe a 1-day-old male infant with classical TCS presentation. A 5-bp deletion in exon 22 of the TCOF1 gene (3469del ACTCT) was found to cause a premature stop codon. This is the first report of TCOF1 gene mutation in the Taiwanese population.

Mutations and new polymorphic changes in the TCOF1 gene of patients with oculo-auriculo-vertebral spectrum and Treacher-Collins syndrome.

Oculo–auriculo–vertebral spectrum, the exact genetic predisposition of which has not yet been resolved, is characterized by varying degrees of the prevalently unilateral underdevelopment of craniofacial structures and spinal anomalies. Here, we analyzed four cases exhibiting multiple features of oculo–auriculo–vertebral spectrum and one case with Treacher–Collins syndrome. The cranium was analyzed using three-dimensional computed tomography, which reliably identifies craniofacial malformations. We detected one typical oculo–auriculo–vertebral spectrum patient who had a missense mutation in exon 9 of the TCOF1 gene complex and two silent mutations in exons 10 and 23, three partial oculo–auriculo–vertebral spectrum patients who had no detectable mutations in the TCOF1 gene complex, and one Treacher–Collins syndrome patient who had a nonsense mutation in exon 14. All five patients had eight previously reported polymorphic changes in the TCOF1 exons 10, 11, 12, 16, 21, 22, and 23, and four unreported polymorphisms in exons 9, 17, and 22 that were also detected in 51 Taiwanese control patients. These observations strongly suggest that the TCOF1 genetic changes observed in these five patients might be related to oculo–auriculo–vertebral spectrum symptoms.

A MID1 gene mutation in a patient with Opitz G/BBB syndrome that altered the 3D structure of SPRY domain

Mutations in the MID1 gene result in X‐linked Opitz G/BBB syndrome (OS), a disorder that affects development of midline structures and comprises hypertelorism, cleft lip/palate, hypospadias, and laryngo‐tracheo‐esophageal abnormalities, and, at times, neurological, anal, and cardiac defects. MID1 gene abnormalities include missense, nonsense, and splicing mutations, small insertions, small deletions, and complex rearrangements. Here, we present a patient with Opitz G/BBB syndrome and a unique MID1 gene point mutation c.1703T

Study of leptin levels and gene polymorphisms in patients with central precocious puberty

Introduction:Three single-nucleotide polymorphisms (SNPs) in the leptin (LEP) or leptin receptor (LEPR) genes were assessed for their association with central precocious puberty (CPP).Results:The control group with the A/G SNP at LEPR 223 or A/G SNP at LEPR 109 exhibited significantly higher peak luteinizing hormone (LH) levels. The leptin level in the CPP group was significantly higher than that in the control group, but SNPs in either LEP or LEPR gene could not explain this observation.Discussion:In conclusion, SNPs at LEPR 223 and LEPR 109 were significantly associated with higher levels of LH in girls without CPP, but none of the genotypes at these SNPs were significantly associated with CPP.Methods:The SNP genotypes of LEP (polymorphism at promoter at nt-2548) and LEPR (223A/G, 109A/G) of 219 healthy girls and 249 girls diagnosed with CPP were compared. Allele frequencies in SNPs were compared with anthropometric measures, circulating leptin, hormones (estradiol, follicle-stimulating hormone, and LH), and lipid concentrations for CPP risk.

Benign familial neonatal convulsions: novel mutation in a newborn.

Benign familial neonatal convulsions are a rare, autosomal-dominant form of neonatal epileptic syndrome. It can occur 1 week after birth, and usually involves frequent episodes, but with a benign course. The diagnosis depends on family history and clinical features. The mutant gene locates at 20q13, a voltage-gated potassium-channel gene (KCNQ2). Our patient exhibited an uneventful delivery course and onset of seizures at age 2 days. The general tonic seizures were unique and asymmetric, with frequencies of >20 per day. Results of examinations were within normal limits, including biochemistry and brain magnetic resonance imaging. Abnormalities included a small ventricular septum defect on cardiac sonography unrelated to the seizures, and nonspecific, multiple, high-voltage sharp waves and spike waves occurring infrequently in the central region on electroencephalogram. After phenobarbital and phenytoin use, the seizures persisted. On day 12, another antiepileptic drug, vigabatrin (unavailable in the United States), was used, and seizures decreased. A novel mutation of KCNQ2 was identified from a blood sample. The baby had occasional seizures with drug treatment at age 3 months. Benign familial neonatal convulsion should be considered in a baby with a unique seizure pattern and positive family history. Genetic counseling and diagnosis are mandatory.

A polymorphism in the leptin receptor gene at position 223 is associated with growth hormone replacement therapy responsiveness in idiopathic short stature and growth hormone deficiency patients.

We hypothesized that responses to growth hormone (GH) therapy by idiopathic short stature (ISS) and growth hormone deficiency (GHD) patients were associated with single nucleotide polymorphisms (SNPs) in the leptin (LEP) and leptin receptor (LEPR) genes. We retrospectively enrolled ISS (n = 32) and GHD (n = 38) patients and forty healthy age-and gender-matched children. They were genotyped for the LEP promoter at nt.-2548, and LEPR K109R and LEPR Q223R polymorphisms. Clinical and laboratory variables were determined before and after 2 years of GH treatment. ISS patients with G/A or A/A genotypes of the LEPR Q223R SNP had a significantly higher height velocity (cm/y) than ISS patients with the G/G genotype at 2 years after GH treatment. For GHD patients, G/A or A/A genotype of the LEPR K109R SNP was associated with higher body weight, higher BMI, and higher weight velocity than patients with the G/G genotype before GH treatment, but not after GH treatment. G/A or A/A genotype of the LEPR Q223R SNP was associated with a significantly higher body weight, higher height velocity before treatment, but not after GH treatment. G/A or A/A genotype of the LEPR Q223R SNP was associated with a significantly higher weight velocity before treatment, but a significantly lower weight velocity was found at 2 years after GH treatment. These results suggest LEPR Q223R SNP (rs1137101) is associated with outcomes of GH replacement therapy in ISS and GHD patients.

Leptin expression and leptin receptor gene polymorphisms in growth hormone deficiency patients

Growth hormone deficiency (GHD) patients have lower weight, height, bone age, insulin-like growth factor 1 (IGF-1) levels, GH levels, fat metabolism and skeletal growth. The association of leptin with GHD characteristics and the effect of gene variants of leptin on GHD are unknown. Our aim was to examine the association of circulating leptin levels and common genetic variants in leptin (LEP) and leptin receptor (LEPR) genes with anthropometric measures, circulating hormone concentrations and GHD. A case control study of 125 GHD cases and 159 control subjects were characterized for bone age, body mass index (BMI), height, weight, leptin, IGF-1, GH and their genotype at the leptin promoter G-2548A, and LEPR variants, K109R and Q223R, at Chung Shan Medical University Hospital. Leptin levels were significantly associated with lower bone age, weight and BMI in GHD patients. Leptin levels were also significantly associated with reduced IGF-1 levels in girls but not boys in both groups. The frequency of LEPR223 [A/G or A/A] genotype was significantly higher than the LEPR223 G/G genotype in the GHD group. The LEPR223 [A/G or A/A] genotype was significantly associated with increased weight and BMI in the control group, but not in the GHD group. In conclusion, the GHD group carried a significantly higher frequency of the LEPR [G/A or A/A] genotype and of the A allele (LEPR223R). The LEPR223R polymorphism affected weight and BMI in control, but not in GHD patients, suggesting that the effect of LEPR223 [A/G or A/A] genotype was counteracted by other factor(s) in GHD patients.

De Novo Incontinentia Pigmenti in Female Twins

The cutaneous lesions of incontinentia pigmenti classically evolve in stages, beginning with erythematous vesicular rash and bullae, followed by verrucose lesions, with an eventual macular pattern of splashed or whorled hyperpigmentation. We describe female twins presenting with the classic form of cutaneous expression. Ophthalmologic examination revealed abnormal vascular proliferations in the peripheral retinas in twin B. Several studies have confirmed linkage of familial incontinentia pigmenti to chromosome Xq28, with the factor VIII gene in Xq28 identified as the locus for incontinentia pigmenti. Two-hundred kilobases proximal to this locus, the gene for NEMO (NF-kappaB essential modulator)/IKKgamma (I kappaB kinase-gamma) has been mapped. We describe herein female twins with incontinentia pigmenti caused by a de novo mutation of this locus, as demonstrated by diagnostic polymerase chain reaction.

Interstitial Deletions of the Short Arm of Chromosome 4 in a Patient With Mental Retardation and Focal Seizure

Interstitial deletion of the proximal short arm of chromosome 4 has rarely been described. This defect is associated with variable clinical manifestations, including mental retardation, unusual facial appearance, and minor limb abnormalities. We describe a girl diagnosed with moderate mental retardation and seizures with an interstitial deletion of the short arm of chromosome 4 [46, XX, del(4)(p12p15.2)].

Persistent falcine sinus and unilateral renal agenesis in a girl with Sotos syndrome.

Sotos syndrome is an overgrowth syndrome characterized by distinctive facial features, developmental delay, and macrocephaly. Here, we present a 10-year-old girl with prenatal and postnatal overgrowth, prominent forehead, pointed chin, and advanced bone age. She also has a persistent falcine sinus in the posterior falx cerebri, patent ductus arteriosus, unilateral renal agenesis, and scoliosis. A pituitary macroadenoma was also found with external compression of the inferior aspect of the optic chiasm. We identified a de novo missense mutation of the NSD1 (nuclear receptor-binding SET domain protein 1) gene in this patient. Computational three-dimensional structural analysis revealed that the NSD1 mutation induced major alterations.