Newborn screening for Krabbe disease: the New York State model.

Krabbe disease is a rare inherited neurologic disorder affecting the central and peripheral nervous systems. The disease has four phenotypes: early infantile, later onset, adolescent, and adult. The only known treatment is hematopoietic stem cell transplantation, which is, in the early infantile form of the disease, most beneficial if performed before onset of clinical symptoms. In August 2006, New York State began screening all newborns for Krabbe disease. A rapid and accurate technique for assessing galactocerebrosidase activity and performing DNA mutation analysis had been developed. Interpreting these results was limited, however, because neither enzyme activity nor genetic mutation reliably predicts phenotype. A series of initiatives were therefore developed by a multidisciplinary group of neurologists, geneticists, metabolic pediatricians, neurodevelopmental pediatricians, and transplant physicians (the Krabbe Consortium of New York State) to enhance the effectiveness of the newborn screening program. A standardized clinical evaluation protocol was designed based on the available literature, criteria for transplantation for the early infantile phenotype were formulated, a clinical database and registry was developed, and a study of developmental and functional outcomes was instituted. This multidisciplinary standardized approach to evaluating infants who have positive results on newborn screening may serve as a model for other states as they begin the process of screening for Krabbe disease and other lysosomal storage disorders.

Absence of mutation in the follicle-stimulating hormone receptor gene in severe primary hypothyroidism associated with gonadal hyperstimulation.

BACKGROUND: Severe hypothyroidism can cause a distinct form of precocious puberty in children, characterized by delayed skeletal maturation, predominance of FSH-mediated effects over LH-mediated function, and reversal of sexual precocity upon thyroid hormone replacement. The etiology of this unusual form of precocious puberty in children remains poorly understood. Recently, three mutations of the FSH receptor gene have been identified in women with spontaneous ovarian hyperstimulation during pregnancy. All three mutated receptors displayed abnormally high sensitivity to hCG which caused gonadal stimulation. Two of these mutations displayed concomitant increase in sensitivity of the mutated receptor to TSH. In this report, we describe four children with primary hypothyroidism and gonadal hyperstimulation. The aim of this study was to determine whether these patients' gonadal hyperstimulation is due to a mutation in their FSH receptor gene. METHODS: DNA was extracted from all four patients with primary hypothyroidism and gonadal stimulation. The entire FSH receptor gene was sequenced and analyzed. RESULTS: Direct sequencing of these patients' FSH receptor gene did not demonstrate any mutation, proving that the cause of gonadal stimulation in these patients is not due to the increased sensitivity or constitutive activation of a mutated FSH receptor. CONCLUSIONS: The elevated TSH in these patients and prior demonstration of the in vitro ability of TSH to bind to the FSH receptor lead us to hypothesize that the gonadal stimulation in these patients is TSH-mediated. The fact that gonadal stimulation is not seen in all patients with severe hypothyroidism raises the question as to whether polymorphisms of the FSH receptor gene and/or possible changes in the TSH molecular structure may contribute to the TSH-mediated activation of the FSH receptor.

Ethical Considerations in Balancing Parental Autonomy With Protecting a Child With Epilepsy From Harm.

Neurologists are expected to accommodate parental decisions in the medical care for their child, unless the parental decision places the child at an unnecessary risk of serious harm. Sometimes, respect for parental autonomy is in conflict with the physician's professional obligation to protect the patient from harm and to optimize treatment for a particular disease or condition. This case illustrates an ethical dilemma created when the neurologist and parent disagree about the most appropriate medical treatment for a child with epilepsy. Viewing the disagreement within an ethical framework, however, provides the parties to the disagreement with an opportunity to understand the beliefs and motivations of everyone involved and creates the potential for an outcome based upon the child's best interest.

Cyanotic episodes in a male child with fragile X syndrome.

A 9-year-old male with a diagnosis of fragile X syndrome (FXS) was evaluated for cyanotic episodes of unknown etiology. Clinical observation revealed frequent episodes of hyperventilation lasting several minutes, only while the patient was awake. This was followed by apnea associated with cyanosis and oxygen desaturation. Polysomnogram confirmed episodic central apnea temporally associated with hypocapnia, only during the awake state. Extensive evaluation failed to reveal other neurological, cardiac, gastrointestinal, or pulmonary etiologies for the events. The clinical observations and investigations allowed us to conclude that the patient's cyanotic episodes were caused by primary behavioral hyperventilation in the awake state. Similar behaviors have been reported in children with a variety of diagnoses but to our knowledge have not been previously reported in children with FXS. Treatment for this unusual behavior in FXS consists of reassurance and behavior modification to decrease the frequency and severity of the cyanotic episodes.