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.