دراسة حالة الكيمياء السريرية

Clinical Chemistry Case Study

•  The study covers newborn examinations, pyruvate dehydrogenase complex deficiency, and neonatal hypoglycemia.
•  The purpose of a newborn examination is to detect abnormalities and congenital malformations to allow timely treatment.
•  Congenital malformations are defects present at birth, ranging from cosmetic (like birthmarks) to life-threatening (like intestinal malpositions).
•  Causes of birth defects include genetic defects (10-15%), teratogens (7-10%), multifactorial causes (30-35%), and unknown factors (~50%).
•  The Apgar score assesses a newborn's condition at 1 and 5 minutes after birth, evaluating activity, pulse, grimace, appearance, and respiration.
•  General newborn examination checks color, well-being, activity, and obvious malformations.
•  Head examination involves measuring head circumference, checking fontanelles (soft spots), and assessing head size (macrocephaly vs microcephaly).  
•  A macrocephalic head is abnormally large, and may be normal or due to conditions like brain enlargement (pachygyria), water on the brain (hydrocephalus), bone overgrowth (cranial hyperostosis), or other conditions.
•  A microcephalic head is smaller than normal, and may be related to genetic, chromosomal, and/or environmental factors.
•  Facial examination verifies normalcy of face, chin, mouth, lips, palate, including cleft lip and palate defects, and checking nose (2 nostrils) with potential Choanal atresia.
•  Chest examination assesses shape, symmetry, location of nipples, and presence of accessory nipples.
•  Abdomen checks for distention, liver/spleen enlargement, and abnormal masses (like umbilical hernia).
•  Umbilicus is checked for adequacy of cord tie or clamp, and presence of 3 blood vessels (2 arteries and 1 vein).
•  Abdominal wall malformations (like omphalocele and gastroschisis) are noted where internal organs remain outside the abdomen.
•  Limb examination verifies normalcy of limbs, fingers, and toes, and signs like syndactyly (fused fingers), brachydactyly (shortened fingers), and club feet.
•  Back/spine examination assesses for abnormalities along the midline (e.g. birthmarks, dimples, tufts of hair), which could indicate spinal issues like spina bifida.
•  Neural tube defects include anencephaly, encephalocele, and spina bifida.
•  Anencephaly is the absence of parts of the brain, skull, and scalp.
•  Encephalocele is a sac-like protrusion of brain tissue through an opening in the skull.
•  Spina bifida is a malformation where the bones around the spinal cord don't close completely.
•  Neurological examination assesses muscle tone and nerve function; assessing floppy babies.
•  Newborn examination sheets document weight, head circumference, and length.
•  Ballard score assesses gestational age based on physical and neuromuscular maturity.
•  Gestational age is assessed and classified as Appropriate for Gestational Age (AGA), Small for Gestational Age (SGA), or Large for Gestational Age (LGA).
•  Cases of identical twins (Ann and Elizabeth) presented with a history, examination, and testing.
•  Twins had sustained recurrent upper respiratory illnesses (more severe in Elizabeth).
•  They presented with feeding difficulties, failure to thrive, hypotonia, microcephaly, and delayed development.  
•  Elizabeth specifically showed ocular hypertelorism (increased distance between eyes), pseudoathetosis (involuntary movements).
•  MRI showed mild fetal atrophy and increased signals in periventricular/subcortical white matter, indicative of myelination abnormalities and likely cerebral palsy.
•  Neurobehavioral tests were conducted, with developmental age results documented.
•  Advanced testing showed profound hypotonia, peripheral neuropathy, and normal sleep-EEG.
•  A ketogenic diet improved psychomotor function and was well tolerated.
•  Metabolic acidosis (higher lactate levels) was more profound in Elizabeth.
•  Reduced PDC activities in blood lymphocytes and fibroblasts were diagnostic for pyruvate dehydrogenase complex deficiency.
•  Diagnosis highlighted an inborn metabolic error (specifically, PDC deficiency) affecting pyruvate oxidation and increasing lactic acid.
•  This deficiency prompted specialized treatment.
•  Treatment included high-fat diets to provide an alternative energy source (acetyl-CoA), thiamine supplementation.
•  Dichloroacetate (DCA) was used to increase residual enzyme activity.  
•  Case studies presented a detailed analysis of hypoglycemia in infants born to mothers with diabetes.
•  History includes diabetic mother, multiple episodes of hyperglycemia (high blood sugar).
•  Presentation had difficulty maintaining adequate blood glucose levels in early life.
•  Conditions like umbilical cord accidents, or placenta issues, were ruled out. Hypoglycemia was predominantly related to the maternal diabetic management.
•  Treatment included frequent glucose monitoring, supplemental glucose (IV), and potentially specific medications (steroids, potentially, etc.).  
•  Diagnosis emphasized the impact of maternal diabetes on fetal development, complications of hypoglycemia, and possible neurological damage from insufficient oxygen supply.
• Detailed clinical presentation with lab reports of the infants and their subsequent development as the cases progress into the future.