Albright like syndrome

2q37 microdeletion syndrome is a chromosomal anomaly involving deletion of chromosome band 2q37 and manifests as three major clinical findings: developmental delay, skeletal malformations and facial dysmorphism.^[1]

The monosomy can be pure or can be associated with additional chromosomal imbalances.

The deletion involves the terminal region of chromosome 2 with breakpoints at or within band 2q37. Band 2q37 contains three sub-bands with over 80 genes being located in the 2q37.1-q37.3 region.

A few genotype–phenotype correlations have been identified including a critical region for the Albright hereditary osteodystrophy(AHO)-like phenotype and candidate genes for brachymetaphalangism, obesity and the autistic behavioral spectrum.

• Major malformations occur in 30% of patients with 2q37 deletions. Congenital heart, gastrointestinal (30% of patients), genitourinary (11% of cases) and central nervous system malformations (6% of patients) have been reported.
• Hypotonia is often present.
• Seizures are described in 35% of patients and behavioral anomalies are reported in about 30% of cases.
• Repetitive behavior and severe communication and social interaction deficits, stereotypic movements, intermittent aggressivity, hyperactivity, attention deficit disorder, obsessive-compulsive disorder and sleep disturbances are the characteristic features of a distinct subtype of autism associated with the 2q37 deletion.

The differential diagnosis should include other segmental aneusomy syndromes and Prader-Willi syndrome (see this term). AHO (pseudohypoparathyroidism; PHP) and pseudo-PHP (PPHP; see these terms) should also be included in the differential diagnosis but calcium, phosphorus, and parathormone levels are in the normal range in patients with deletion 2q37.

Incidence is estimated at less than 1 in 10,000 and more than 100 individuals have been reported.

Screening for a translocation should also be conducted as the deletion may be the result of the transmission of a derivative chromosome.

The prognosis depends on the malformations (cardiac, cerebral or intestinal) associated with the 2q37 deletion.

Most of the initially reported patients had an Albright hereditary osteodystrophy-like phenotype (referred to as AHO3) with developmental delay or intellectual deficit, short stature (23% of patients), a tendency toward obesity with age, and brachymetaphalangism (50% of patients).

• Sparse scalp hair
• Eczema is often present.

• Microcephaly or Macrocephaly
• Round face
• Prominent forehead
• Midface hypoplasia
• Thin vermillion border of the lips

• Upslanting palpebral fissures
• Deep-set eyes
• Sparse and arched eyebrows

• Depressed nasal bridge
• Deficient nasal alae
• Prominent columella
• V-shaped appearance of the nasal tip

• High-arched palate

Nipples are often widely set, distally placed or supernumerary.

• Fifth finger clinodactyly
• Small feet/hands
• Syndactyly of the fingers or toes
• Persistent fetal finger pads
• Single palmar crease

Diagnosis relies on cytogenetic analysis and molecular characterization.

Management of deletion 2q37 patients should be multidisciplinary and include a comprehensive evaluation of the major clinical criteria.

Speech, physical and occupational therapy are required.

Antenatal diagnosis is feasible and genetic counseling should be proposed.

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