A rare form of ectodermal dysplasia with premolar
aplasia, hyperhidrosis, premature cavities, and premature whitening of the
Premolar Aplasia, Hyperhidrosis, and
Premature Cavities Syndrome; PHC Syndrome.
Autosomal dominant with high penetrance.
Unknown, but PHC syndrome belongs to the
heterogeneous group of ectodermal dysplasias that includes more than 150
diseases with various inheritance modes and genetic heterogenicity. In
ectodermal dysplasia, the initial factor seems to be a perturbation of
Premature whitening of the hair with characteristic
dental defects and a family with similar history.
Dental affection is the most frequent sign.
Anodontia or oligodontia can affect all teeth, but missing premolars are the
most characteristic. Abnormal dental position and tooth shape anomaly may be
observed. Premature whitening of hair can appear even in childhood and may
be associated with poorly formed dermatoglyphs and distal digital creases.
Increased sweating of the hands and feet are very frequent (hyperhidrosis).
No other disorders are associated
with this particular syndrome. However, because of a mild depression of the
immune system and a defect in the respiratory mucous glands, other forms of
ectodermal dysplasia often show a predisposition to respiratory tract
infections, which are potentially life-threatening. No such reports exist
specifically for this syndrome, but nevertheless should be kept in mind when
assessing the patient. Evaluate dental position, aspect, and mobility, and
severity of hyperhidrosis.
No reports of anesthetic experience with
these patients are available. Patients may present for surgical management
of hyperhidrosis. Extremity lesions can interfere with pulse oximetry.
Direct laryngoscopy must be done very carefully considering the dental anomalies.
Hyperhidrosis must be evaluated
before use of parasympatholytic drugs (flush, hyperthermia more frequent
Far more than 100 different
forms of ectodermal dysplasia are known; only a few are mentioned here to
show the wide variety of this entity.
Rapp-Hodgkin Hypohidrotic Ectodermal Dysplasias: Autosomal
dominant inherited anhidrotic ectodermal dysplasia with cleft lip/palate,
hypodontia, hair anomalies and alopecia in adulthood, and nail anomalies.
Christ-Siemens-Touraine Syndrome: Inherited disease characterized
by absence of sweat glands (anhidrosis, distorted heat regulation), and
sebaceous glands (xerosis), hypotrichosis, poor dental development, and
facial abnormalities (prominent forehead, thick lips, saddle nose).
Psaume Syndrome (Orofaciodigital Syndrome Type I): A syndrome with X-linked dominant
transmission or sporadic (75%) occurrence with oral (tongue and dental
anomalies, cleft lip/palate), facial (hypertelorism, telecanthus,
micrognathia), digital (brachydactyly, syndactyly, duplication of hallux),
cerebral (cerebellar atrophy, agenesis of the corpus callosum, Dandy-Walker
malformation, mild mental retardation), and renal anomalies (polycystic
kidney disease). Almost all affected patients are females, although some
affected males have been reported.
Ellis-van Creveld Syndrome: Autosomal recessive inherited syndrome
with congenital cardiac defects, pulmonary hypoplasia because of a small
chest, dwarfism, polydactyly, nail dystrophy, and dystonias.