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Genetically transmitted polymalformative syndrome
characterized by hypoparathyroidism, growth retardation, developmental
delay, seizures, and facial dysmorphism (e.g., micrognathia).
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Hypoparathyroidism with Short Stature, Mental
Retardation, and Seizures; Kalam Hafeez Syndrome.
++
Autosomal recessive. The genetic locus is on the short arm of chromosome 1 at position
42-43 (1q42-q43).
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Virtually undetectable levels of parathyroid
hormone resulting in hypocalcemia associated with hypophosphatemia. Growth
hormone and insulin-like growth factor levels were also found to be low in
affected children. Treatment with human growth hormone produced a rapid
increase in the height and weight of one affected 5-year-old child. It was
speculated that the hypothalamus plays a role in the regulation of both
parathyroid hormone and growth hormone.
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Clinical features plus the onset of hypocalcemia with
very low parathyroid hormone levels, usually in the newborn period. Usually
consanguineous parents.
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Early onset hypocalcemia, which may be
asymptomatic, associated with hyperphosphatemia. Very low parathyroid
hormone levels, and possibly low growth hormone and insulin-like growth
factor. Consequently, patients have retarded growth (more than 2 SD
[standard deviations] below the mean). Facial dysmorphism is very
consistent, especially within families with more than one affected child:
microcephaly, deep-set eyes, depressed nasal bridge with beaked nose, long
philtrum, thin upper lip, micrognathia, and large, floppy ear lobes. Most
children have skeletal defects, such as medullary stenosis. Developmental
delay is usual. Seizures may occur. Reduced numbers of some T-cell subsets
have been detected in some patients, but immunological function seems
normal.
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An anesthesiology consultation is recommended before elective surgery. Detect and treat
hypocalcemia/hyperphosphatemia. Evaluate the patient carefully for potential difficult
tracheal intubation.
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A difficult direct laryngoscopy and tracheal
intubation may be expected, especially in patients with micrognathia. If so, spontaneous
respiration should be maintained until the airway is secured and lung ventilation
confirmed. Considerations of uncorrected hypocalcemia: long QT interval and associated
dysrhythmias, hypotension caused by peripheral vasodilation and ventricular dysfunction,
seizures, and increased neuromuscular irritability (prone to laryngospasm). Respiratory or
metabolic acidosis can further decrease ionized calcium by increasing protein binding, and
thus increase the likelihood of the above-mentioned considerations. Affected patients may
be more sensitive to nondepolarizing muscle relaxants. Older children may be uncooperative
as a result of developmental delay.
++
Increased sensitivity to muscle
relaxants.
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DiGeorge Syndrome: Recurrent infections,
defective thymus functions, heart defects, and characteristic facial
features caused by a deletion in chromosome 22.
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Kenny-Caffey Syndrome: Congenital
hypoparathyroidism associated with short stature, mental retardation,
seizures, and a characteristic physiognomy. Cortical thickening of bones
(osteosclerosis) and hypocalcemia. Autosomal recessive, which maps to the
same region (1q42-q43); probably allelic to Sanjad-Sakati syndrome.
Kalam MA, Hafeez W: Congenital hypoparathyroidism, seizure, extreme
growth failure with developmental delay and dysmorphic features—Another
case of this new syndrome.
Clin Genet 42:110, 1992.
[PubMed: 1395080]
Kelly TE, Blanton S, Saif R, et al: Confirmation of ...