Albright like syndrome
Synonyms and keywords: 2q37 microdeletion syndrome; Albright hereditary osteodystrophy 3; Albright hereditary osteodystrophy-like syndrome; brachydactyly-intellectual deficit; monosomy 2q37-qter

# Overview
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.

# Pathophysiology

## Genetics
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.

## Associated Conditions
- 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.

# Differentiating 2q37 microdeletion syndrome from other Diseases
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.

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

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

# Natural History, Complications, and Prognosis
The prognosis depends on the malformations (cardiac, cerebral or intestinal) associated with the 2q37 deletion.

# Diagnosis

## Symptoms
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).

## Physical Examination

### Appearance of the Patient

### Skin
- Sparse scalp hair
- Eczema is often present.

### Head
- Microcephaly or Macrocephaly
- Round face
- Prominent forehead
- Midface hypoplasia
- Thin vermillion border of the lips

### Eyes
- Upslanting palpebral fissures
- Deep-set eyes
- Sparse and arched eyebrows

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

### Throat
- High-arched palate

### Chest
Nipples are often widely set, distally placed or supernumerary.

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

## Laboratory Findings

### Biomarker Studies
Diagnosis relies on cytogenetic analysis and molecular characterization.

# Treatment
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.

### Genetic Counseling
Antenatal diagnosis is feasible and genetic counseling should be proposed.