Byoung Hoon Yoo

Congenital Epidermoid Cyst of the Oral Cavity: Prenatal Diagnosis by Sonography

Epidermoid cysts are benign developmental anomalies that are rarely observed in the oral cavity of neonate. If large in size, especially in the developing fetus or newborn infant, they can cause swallowing difficulty and occasionally respiratory difficulty. We report a case of epidermoid cyst in the oral cavity detected prenatal sonography. The sonographic finding was large cystic mass, measuring 30×25 mm. In this case, supplies and equipment for an emergency tracheostomy were made available prior to the delivery. However, the infant did not require intervention to secure the airway. The lesion was surgically excised, and histologic diagnosis was epidermoid cyst. After 6 months of follow up, the cyst had not recurred. This case illustrates the value of accurate prenatal diagnosis and planned perinatal management using a team approach.

A Tailgut Cyst—Cystic Mass Diagnosed by Prenatal Ultrasonography

Tailgut cysts are congenital lesions found in the presacral space. These have been mainly identified in adults and are rare in children, especially neonates. Here, we present the case of a neonate with a presacral cystic mass detected by prenatal ultrasonography that was diagnosed as a tailgut cyst after postnatal surgical removal. When a presacral cyst is encountered, tailgut cyst should be considered in the differential diagnosis.

Early congenital syphilis presenting with skin eruption alone: a case report

Congenital syphilis is one of the most well-known congenital infections, yet it remains a worldwide public health problem. Congenital syphilis can involve any organ system and present with various symptoms. However, early diagnosis of congenital syphilis is difficult because more than half of the affected infants are asymptomatic, and the signs in symptomatic infants may be subtle and nonspecific. Here, we report a case of congenital syphilis with only a skin rash, which led to a delay in diagnosis. This case indicates that congenital syphilis should be considered throughout early childhood.

Two Novel Missense Mutations Observed in Nonketotic Hyperglycinemia

Nonketotic hyperglycinemia, also known as glycine encephalopathy, is an autosomal recessive disorder of an inborn error of the glycine metabolism, caused by deficiency in the mitochondrial glycine cleavage enzyme. The majority of cases are caused by mutations in P-protein, one of the four components of the glycine cleavage enzyme, glycine decarboxylase. We describe a male neonate with hypotonia, hiccups, and persistent apnea, but without seizures. The patients glycine level in cerebrospinal fluid and plasma was 328.3 nmol/mL (reference value, 2.2-14.2 nmol/mL) and 1439 nmol/mL (reference value, 232-740 nmol/mL), respectively. The cerebrospinal fluid/plasma ratio of 0.228 represented an increase (normal range, <0.04). Two novel heterozygous missense mutations (c.1130C>T (p.A377V) and c.2081_2088del (p.A694DfsX11) in exons 8 and 18) in the glycine decarboxylase gene confirmed the diagnosis of nonketotic hyperglycinemia.

The first case of X-linked Alpha-thalassemia/mental retardation (ATR-X) syndrome in Korea.

Mutation of the ATRX gene leads to X-linked alpha-thalassemia/mental retardation (ATR-X) syndrome and several other X-linked mental retardation syndromes. We report the first case of ATR-X syndrome documented here in Korea. A 32-month-old boy came in with irritability and fever. He showed dysmorphic features, mental retardation and epilepsy, so ATR-X syndrome was considered. Hemoglobin H inclusions in red blood cells supported the diagnosis and genetic studies confirmed it. Mutation analysis for our patient showed a point mutation of thymine to cytosine on the 9th exon in the ATRX gene, indicating that Trp(C), the 220th amino acid, was replaced by Ser(R). Furthermore, we investigated the same mutation in family members, and his mother and two sisters were found to be carriers.

Congenital Chloride Diarrhea in Dizygotic Twins

Congenital chloride diarrhea (CLD) is a rare inherited autosomal recessive disorder. Mutations of the solute carrier family 26 member 3 gene cause profuse, chloride ion rich diarrhea, which results in hypochloremia, hyponatremia and metabolic alkalosis with dehydration. If a fetal ultrasound shows bowel dilatation suggestive of bowel obstruction, or if a neonate shows persistent diarrhea and metabolic alkalosis, CLD should be considered in the differential diagnosis. The severity of CLD varies, but early detection and early therapy can prevent complications including growth failure. We report a case of dizygotic twins affected by CLD who had been born to non-consanguineous parents. Both of them showed growth failure, but one of the twins experienced worse clinical course. He showed developmental delay, along with dehydration and severe electrolyte imbalance. He was diagnosed with CLD first at 6-month age, and then the other one was also diagnosed with CLD.